Train or Bus

No way would I take the bus. I am too old to try to sleep all night in a seat, and arrive in the morning in the same clothes.

The third option is a train. This takes 8½ hours and costs from €59.90. Saves all that getting to and from airports (time and cost), and getting through the airport. there is no overnight train. For example (random date in March):

Wien Hbf depart 09:15, Berlin Hbf (tief) arrive 17:29, € 79,90
Wien Hbf depart 11:15, Berlin Hbf (tief) arrive 19:29, € 89,90
Wien Hbf depart 13:15, Berlin Hbf (tief) arrive 21:29, € 59,90
Wien Hbf depart 15:15, Berlin Hbf (tief) arrive 23:33, € 59,90

The key factor is whether you can sleep sitting up. It's a shame to arrive in a new city with lots to see and find yourself asleep on your feet.

I would never take the bus today - I'm too old, and I've never been crazy about long bus rides anyway. I'd never sleep on the bus - I can't sleep on international flights overnight either.

However, if I were younger and really on a tight budget? I might take the bus and just live with being a little groggy the next day. I wouldn't do it say the day after flying into Europe from overseas, but I can survive being groggy on arrival day from the overnight flight; I could do it with the bus if I really had to. If I were doing it today, I would probably take a day time train vs. flying or taking the bus, however.

Taking the bus is like flying for 8 hours but with a rest stop. Some people can sleep others no. I've done it before something similar when I was younger (Paris to Amsterdam, London to Paris) but will never do it again as long as I can pay not to as I do not like any bus or train travel over 3 hours. However I look back at the pictures of the whole of those trips to Europe where I took bus rides that long as fond memories.
It is up to you.

Further - whether or not you can sleep on the bus depends on YOU; some people can, some can't. I can't. If you can, maybe the bus would be OK.

The train does not work out for me unless I want to lose time in Vienna. I need to leave Vienna in the evening whether it's by bus or plane. In any case with the price you gave it's the same price as me flying. I'm always kind of surprised when people say I will be at the airport for hours and hours. I've taken flights within Europe on low budget carriers and it was never like that. The airports aren't even a great distance from where I would be staying in both cities.

again It is up to you.

You can't take the 20:41 train from Vienna that gets into Berlin at 9:06 the next morning?

The 20:41 train is actually a good idea even though it's 4 hours longer. I cannot see to get pricing though for it for just a standard ticket with the cheapest bed. Used Bahn.

Good suggestion Andrew. To reserve a couchette on that train ends up being just under 93Euros ($115USD). Not bad and I'm thinking about that now! I've never been in (on?) a couchette before. I see they have 6beds for women or a 4bed women section. Do you know if the 4 couchette room for women is the same size as the 6 couchette room for women just with more space? It's just 10Euros more to be in a 4 couchette room but it might not be worth it.

Okay the responses here were really helpful. I ruled out the bus because I'm just not sure if I would get any sleep on it.

I'm now between the flight/1 extra night accommodation in Berlin for $157 (still would give me a full day in Vienna that I need) or taking the night train in a female 4 couchette room for $126. I'm slightly leaning towards the flight because I would be able to sleep in a normal room and start the morning in Berlin how late/early I want, but not sure yet because it could be an experience sleeping in a couchette room with complete strangers (never done that before and it does sound like something I should do once). :)

I took a dozen overnight train couchette trips in Europe a decade or so ago. I was stationed in Germany with the Army, and the timing worked well with having to work a full day and then arriving early the next morning in a new city/country for a long weekend.

Bring earplugs, and try to be good and tired the day before so you can fall asleep more easily. I usually managed to get at least 5 hours of sleep in the couchette, which was enough to hit the ground running the next day. Since you lie flat, it's far, far better than trying to sleep sitting up on a bus or plane.

However the worst part was often feeling grubby and unwashed after getting off the train. I stayed in hostels that would usually let me check in in the morning and immediately take a shower. If you can't check in to your hotel until like 3pm, I would skip it and take the flight.

There is the night train option: Wien Hbf to Munich Hbf, then Munich to Berlin. I've done that. The bus option is not a bad one, I would do it. Overnight bus or train both options are no problem as far as sleeping is concerned. In your case take the bus.

I'm sure Flixbus is more comfortable than going Greyhound from SF to LA, which I did a few times 8-10 years ago...all day ride.

I would never DREAM of being trapped on a bus like that. Moreover, I like EasyJet for intra-European travel.

I'm now between the flight/1 extra night accommodation in Berlin for
$157 (still would give me a full day in Vienna that I need) or taking
the night train in a female 4 couchette room for $126. I'm slightly
leaning towards the flight because I would be able to sleep in a
normal room and start the morning in Berlin how late/early I want, but
not sure yet because it could be an experience sleeping in a couchette
room with complete strangers (never done that before and it does sound
like something I should do once). :)

If you want to do this to say that you've done it, go for it. How are the shower facilities on the train? If there is no place to shower and I couldn't check in first thing the next morning at the Berlin hotel without paying extra, $31 extra for flying EasyJet is worth its weight in gold.

How are the shower facilities on the train?

Inexistent in couchette cars (unlike sleeper cars). You can, however, take a shower at Berlin Hbf (€7).

I think a bus is fine, provided it fits my general rule of no more than four hours traveling in a day. When a car, bus or train trip gets longer than four hours, I'll consider a plane or an intermediate stop to break up the trip. I won't take an overnight train or overnight bus both because my limited vacation time has value, and losing sleep ultimately hurts your trip more than saving lodging costs for a night helps.

@ Boba...It is ultimately your decision to make on which option to choose...bus or plane. I take the overnight train to squeeze out an extra day of traveling. Taking an overnight Flixbus is pretty tempting since I never think of that option while I'm over there. Catching the bus sometimes is not close to the main train station, if you think in terms of going from one main train station to another.

I've heard about bus station locations and how airport locations can be in inconvenient areas for people. When I've used Google Maps for my plans, they aren't obstacles.

My gut is leaning towards just flying since I will get a good night's sleep and be able to start my day when I want. The couchette was a good idea but I don't know how well I will sleep there either (I've never taken an overnight train), and then I would have to wait at another train station for 40 minutes before going to Berlin. I like the idea of being able to take a shower in a hotel versus at a train station (has anyone taken a shower at a train station? sounds interesting to me).

I will most likely do the hotel. It just seems the most physically comfortable for me.

In any cases, a lot of the responses here were very, very helpful :)