Small local firm here (public).
When I started here (2008) we used a bunch of different programs for write-up, fixed assets, tax (Lacerte), and billing/timekeeping. We have since switched to Thomson for fully integrated programs across the board. If you take your time to set it up properly, it does a fantastic job of cutting down input time on tax returns by importing the figures directly from the write-up program. The fixed assets module is directly integrated into the tax program as well, reflecting any additions and disposals you have made during the year, as well as having fields that allow you to do apportionment for Municipal income tax returns (a total pain in Ohio IMHO!).
As far as clients go, we push PT although most have already drunk the QB koolaid. I understand that it is our job to handle that stuff (especially in the case of small business/Sch C filers who are typically doing the work AND the accounting), but I like to teach the bookkeeper a bit of self-sufficiency as it tends to save the client in time billed and they can potentially solve their own problems going forward. QB tends to keep the client dumbed down by doing as much as possible to obscure the double-sided entry principle of accounting, and that is detrimental in the long run.
For some of our more sophisticated construction clients, we have recommended Foundation, which is a phenomenal job-costing software that has a steep learning curve but is much more capable than any contractor version of PT/QB.
B 92
A 99
R 90
F 92
Becker Self-Study
OH CPA since 2/18/14