I, too, have been a loyal user of Infopop's products, until now. I started about 3 1/2 years ago using the old UBB software and switched to UBBThreads when it became available. I'd been happy until recently when it seems IP's support has gone down hill. Then, they announced the end of all Threads development and that was the beginning of the end for me. That, along with their seemingly disregard for users input were the 2 biggest reasons for looking elsewhere. I got tired of seeing wanted options being tossed aside by the IP dev group because it wasn't what THEY wanted.
Today, I'm working on converting my Threads forums over to FusionBB after having done beta testing for the past couple of months or so. In fact, I own the #3 license ever issued for FusionBB and along with myself and my team are very excited about the upcoming change.
If Infopop could change their coporate, we are ALWAYS right mentality and start listening more to their users, they might be able to bring their company back around. However, as it is, they are heading down the wrong path by alienating so many loyal users.
However, as Jason said, if their products are doing everything you ask of them, then by all means stick with it, but you might want to look around a bit.