Hi, Nomadgirl, and welcome to the RS Italy forum -
I haven't taken an RS tour so am probably not who you were hoping to hear from! I have, however, spent a lot of time on the forums and don't want your first question to go without at least some sort of response. Also, this will kick your post back up to the top so it'll be more visible to people who may have missed it.
My take, as an independent traveler (so far) myself? Signing up for a tour means cheerfully exchanging the autonomy of making all the arrangements yourself for the convenience of having all that - hotels, restaurants, transport, guide services, etc. - taken care of. Also, some who opt for tours find traveling in the company of others to be a bonus - they enjoy daily camaraderie - and may feel more secure with a group.
It is a trade-off, though, and I'll emphasize that "cheerfully" above as if a few hotel rooms which don't meet personal standards will spoil the trip, then maybe a tour isn't for you? This is especially true if that disappointment would color your ability to abide by the Steve's "no grump" policy for all of their tours. I'm not implying that you would have a problem with that at all but, well, a visibly, audibly, unhappy camper is no fun for everyone else.
Why haven't we taken a tour? Not because we'll have to let them choose our beds for us but because we simply enjoy more time in one place than the tours provide, and the freedom of doing exactly what we want to, when we want to. It is such an important factor of our trips that the convenience of a package isn't worth the trade-off at this time in our lives.
So you may need to weigh how important the accommodations piece is to you? If not being able to choose them yourself is going to cause much anxiety before you go and/or possibly trip-spoiling disappointment once you're there, then you might reconsider if the tour.
The GOOD news is that I ran through all of the reviews for "Heart of Italy" and only one person had a big enough issue with the rooms to make it an issue in their review. One. That's a tiny percentage. We've also stayed in a variety of Italian hotel rooms and while a few have been a bit cramped - smaller rooms than in the U.S. are common - and a little worn around the edges, all have been comfortable and plenty clean enough. Bathrooms, especially, have all been very nice. :O)
(editing to add: I see that 2 others added posts while I was still typing!)