We use QB POS along with QB PRo.
It mostly works well for us, but it crashed ALL OF THE TIME in the beginning. Everytime we added a new product in the database, the POS would crash on us sometime in the next 10 hours. It is not a big deal to reboot, but sometimes it would pop up a screen that said we have exceeded our # of software licenses and would not open. That made us crazy. QB POS online help completely ignored all of the emails I sent them, and also did not return any of my calls. I finally figured out that if you go into the CONTROL PANEL > ADMINISTRATIVE TOOLS > SERVICES there are various background applications that run to support QBPOS and QB. Some of those background applications randomly turn themselves off. After some three hour sessions of rebooting computers over and over and over and over again, I finally found out that these problems could be fixed in a matter of a couple of minutes in the Services section. Any service that relates to QB or QBPOS should be restarted and it would fix the problems. Some of the services would actually switch themselves to Disables, and you would have to enable then restart them.
I strongly believe that Intuit intentionally puts faults in their software to force you to use their customer service (which costs money after a certain amout of time has gone by). If you are tech savvy enough, you can keep these programs running on your own, but it can be very frustrating.
We spent $1500+ on them and are stuck with them... They work fine once you figure out how to coax them into working...
Good luck,
JD