We went through the same struggle before we bought our 2007 210 Versatile (new in 2007). What helped tremendously was renting both a 190 and a 210 for two-week vacations before buying. Our situation may differ in that there were three of us (me, wife, young son), so space (particularly storage space) was a key consideration. I disagree with a previous poster who suggested that there is not a big difference in storage space between a 190 and 210. My opinion is that the difference is substantial and was, in large part, the key factor in our choosing a 210. The other factor was the enclosed bathroom/shower. We really wanted the 190 for the smaller and more convenient size, but in the end the 210 was the right choice due to the additional space and storage capacity. If we were to do it again without young son in consideration, we would opt for the 190.
We have a 2002 RT Popular and also found the single bets too narrow. We put in a double bed mattress and sleep crosswise. This is also more comfortable when parked at the side of a road or curb.
I was also frustrated with the dump system as it was too low to the ground and would not flow over a curb around dump stations. I installed a macerator in the system and can easily pump anywhere and it is much cleaner to work with.