It obviously has to do the type of work you're into but as fast as paving specs change (around here, at least) be sure to plan ahead.
Some of the best mats we've laid were with an Ingersoll DD110 but that machine is old and tired now, going to auction next week but not sure how much can be got for it.
We're running Dynapacs now but we got into a situation where the spec/plans called for a 3" mat with some stiff mix and we simply had hell getting in place density and had to get a bigger roller (from a CC522V to a CC722)
We don't pave all that much, just enough to keep one crew busy. We have a good relationship with several contractors who specialize in it.
The Dynapacs do the job, especially the big one and we very seldom have problems with them but they are special use machines that get extra attention. Reliability is a must....having a key unit go down and losing mix is a really bad day. The other Dynapacs we have, are a mixed bag....the newer single drums are very good but the older, low hour 3 wheel finishers are awful, hard to get parts for and no one wants them if they can get an old school Ingram 3 wheel.