And upgrade is easy, a complete breze; it can take a little bit of time depending on your size, but it's all automated.
I've come from UBB.Classic to UBB.Threads and I must say, if you're into customizations, UBB.Threads makes things much easier.
I was with UBB.Classic since there was just one UBB product as well (can we say freeware anyone?)
UBBDev is still around for new features, styles, coding, etc. for ubb.threads.
Myself, I love UBB.Threads, I've actually had the oppertunity to play with other products (vBulletin, IPB, phpBB, SMF, etc) and UBB.Threads has the cleanest code which is in more logical places, it's also a lot easier to work with, and the people who help with support are great people (no i'm not tooting my own horn :looks around:).
But ultimately, as Rick said, it's all up to personal preferance, but I for one am loving it
