Which tour?

Clare, which ever tour you choose be prepared for it to be the "It it's Tuesday it must Belgium" type trip. Really The Best Europe would take a lifetime to explore. You may get a flavour of some countries many you will get a view of as you pass through by whatever means of transport is used.

Claire, I haven't taken either of those tours, but I've seen several comments on the HelpLine from people that have taken the 14-day Best of Europe tour, and the unanimous opinion seems to be that they were sorry when it ended, and at that point they were wishing they had taken the longer tour. I agree, the tours are expensive but when all is considered, I believe they're very good value. I've taken five so far and plan on taking another one. I can't imagine travelling with any other firm. As you mentioned, the Guides are outstanding! Good luck with your decision and happy travels!

Having taken a Rick Steve's Tour they are not in the "if it's Tuesday it must be XXX" category. There are always a day or two off, and partial days on your own to do as much/little as you want. If this is your first trip to Europe I'd recommend flying into your departure city two or three days ahead. Once you book they will tell you what hotel the tour is staying in and you can book those extra nights in the same hotel. This will give you a chance to settle in and start your tour refreshed. Ditto at the end of the tour if you wish. If you've never been to Europe two weeks will be enough to fry your little brain. While we rarely take a tour Rick's are the only ones I EVER consider. Small, family hotels, local guides, no shopping stops, no tipping, interesting fellow travelers. Just be on the bus on time!

Claire,
I was faced with the same choice. The 21 day tour has (as you would expect) more time on the bus. I get antsy sitting too long, and didn't want more bus time, so I booked the 14 day tour, and added 4 days in Paris on the front end of my trip. The trip is coming up in about 5 weeks, and I'll see if I'm happy with my choice after the trip is over! Both trips get fantasic marks in the Tour Review section, but after adding up the number of bus hours for each trip, my decision was easily made.

I took the 21 day tour and loved it. I added three extra days at the end to stay in Paris. I did not come a day early, and regretted it. The first day was done in a fog. There is very little difference between the 14 and 21 day tour. You will not go to the Cinque Terre for your "vacation from your vacation" on the 14 day and you won't go to Munich on the 21 day, to name a few differences. So, it depends on what you would enjoy more. Again, I decided I was willing to invest both the time and money for the longer trip. It gave me a flavor of which countries I wanted to go back and explore, both on my own and on ETBD Tours. As to the bus, can't avoid the time spent. However, there are plenty of rest breaks. You can catch up on your correspondence, reading and napping. Or spend the time talking to your new friends.
I hope this helps with your decision.

I've only taken a few tours but I always fly out to the meet-up destination a day or two early to avoid any weather or flight delay issues along with allowing myself to rest up and get ready for the tour. On a Christmas Market Tour a friend and I took in 2009 two couples were a day late and their baggage 3 days late due to weather delays....not snow, but rain! They were bummed!

Claire, its interesting to note the posters who seem leary of the 21 day tours are the ones on this thread who have never done the 21 day tour with RS. Having done the 14 day tour I side clearly with those who say take the 21 day tour if you have the time,, you will love it!!! I did not find we ever had "too much bus time" as the few times we had any longer bus time it was a most welcome break to relax and enjoy the scenery( and btw , I took the 14 day Family tour, which meant we had 14 kids on the bus , and none of them found it boring at all) Also, by law, the bus stops every 2-3 hours, the bus driver in required to have breaks that often, so we never did any marathon bus stretches at all.
If you have the time and the money, take the 21 day tour, and especially good advice is to arrive 2 days before. This not only allows you a bit of recovery time from jet lag and travel fatique, but if your luggage is delayed you have time for it to arrive at your hotel . Its also a great opportunity to have a few extra days in the anchor city!