I have a 559. I ride it regularly on the crushed limestone Katy Trail and don't find the lack of suspension to be an issue.

My wife rides a Trail which is quite similar but with a 406 rear wheel. If I had it to do over, I'd get a Trail for myself too. The Trail folds a little more compactly for transportation and winter storage. The trail also has space for a larger behind the seat bag for carrying "stuff". I bought the 559 because I thought that I needed faster gears than the Trail provides but the reality is that I don't.