Our school uses Pastel Partner, across 4 computers for 4 users.
It has been a bit of a resource hog, and it is has crashed a few times, especially once they introduced the drill down feature a while back, our systems were too under powered for that, but since upgrading it's running better.
Yet on the other hand it seems to satisfy the needs of the bursar and bookkeeper just fine. I guess my main gripe at times is getting the package registered (if the internet method fails for some reason) and having the call centre person give you the serial number "J for Juliet, H for hotel, V for Victor" type style.
My dad is an accountant, and uses Pastel too for his small home run accounting business. He also uses an older package called Tas Book Keeper, that while not as advanced as Pastel, was much less resource heavy and has some simple logical things that Pastel doesn't, or that you need to pay stacks extra for.