I've used both of them at different schools for a few years now. Volunteer Builder is very good, and simple to use. At this point, the volunteer coordinator sends out very few requests for volunteers on her own; individual committee chairs have gotten used to using the system and can send out their own requests. The volunteer coordinator mostly uses the system to record volunteer hours. There's a function you can turn on that allows you to set up the system in school and have people log in directly, so that their classroom volunteer time is automatically recorded in the system, for example, but our school system hasn't allowed that feature to be turned on (plus there's not really a good place to put it in the office).
Finance Manager is also very easy to use, and I think it is a huge plus that it is web-based. Quicken (or QuickBooks) is overkill, and you have to make sure that people make backups. I've run into situations two different times now where people have used Microsoft Money or Quicken, and then their hard drive has crashed or something, and all the data is gone!! Why people can't remember to make backups is beyond me, but they can't. In addition, Finance Manager allows other people to have access, so if the Treasurer is sick, stuck in traffic, etc., someone else can pull up the reports. QuickBooks has an online product, but it is more expensive than Finance Manager, and not as easy to use. Anyone who can write a check and balance a checkbook can easily use Finance Manager.
I'm not a fan of the reporting functions in Finance Manager. You can download the reports and manipulate them in Excel, though. That is fine if you have someone who is good with Excel, but someone who needs a system as easy as Finance Manager probably isn't as skilled with Excel as they need to be to manipulate the stuff quickly. There's another online product out there that I think has better reports, and it also allows you to map accounts to the appropriate line items on the 990, but it is more expensive than Finance Manager.
Also, if you call PTOToday and tell them you want ot try Finance Manager, they will probably give you 30 days of free access to evaluate it.