Worth it to spend about 30 hours in Rome?

I don't have a suggestion for a hotel however, you can take the city red bus #110 from the Termini station. It is an HOHO bus that covers over 80 sightseeing destinations with an audio guide. It is a great way to see the highlights. The route takes 2.5 hours. The ticket is good for 24 hours. Sit on top in front for the best views. You can either take the bus to the sights that interest you or the Metro which is very very easy to utilize.

I would argue it is worth it. I have been to Rome twice and really enjoyed it both times. The first time I went to Rome in 94. I left my hostel at about 2 in the afternoon the day I arrived and started following one of Rick's self guided walking tours. Finished that and then just started walking around. By 7pm I hand seen most of the major sites in Rome except the Vatican. I didn't go into all of them/or linger for a long time at them but I had seen them. Oddly I remember that afternoon more than about 95% of the afternoons I have spent in Europe (12 vacations). Just be ready for the heat and have a plan you might just be surprised how much you can see in a short time.

You might also consider a night train on Sunday night from Venice to Rome.

The night train -sleeper- from Venice to Rome is the 771 Marco Polo (I think).

It leaves at 23:30, and arrives in Rome Tiburtina Station at 6:56am.

The prices are really, really good for a sleeper or couchettes. (for two people, much less than you would pay for 1 more nt in Venice, and the day train.).

We got 4 first class couchette tickets with our own cabin on an Amica rate (discount rate) for 45.20EUR per person. FYI.

PS - I've been told there IS bag storage in Tiburtina station, if you need to store bags til check in.

Have a great trip!

Suzanne, I didn't see in your post how much time you are spending in Venice. To me this would help answer your question.

If you will have had plenty of time in Venice then I say go for Rome. But I don't think it would be fun to have had a very short time in 2 cities, if that's what will happen. Better to have plenty of time in 1.
So, how much time will you have had in Venice? (By the way, these are my two favorite cities anywhere!
Have a great trip!

I would say that it's worthwhile to go to Rome. I went to both venice and rome and found that I enjoyed rome more because there was much more to do there. Venice got a bit boring after 2 days for me, but it really is a personal preference.