Dear,

We have searching through the feedback of other site, who have migrated from UBB.Classic to UBB.threads.
The goal was "what can be the possible problems with UBB.threads".
Based on the information we can create a list of advantages and disadvantages, but also we can show how this UBB.Thread can be used.

Advantages

as member you can make other post one of your favorites.
as UBB.Classic board grows it will get slower and functions such as "search" will be next to impossible to run unless you have a dedicated server (posts aren't stored in a database, so server load can be immense). For that reason: huge UBB.Classic boards ... most have been switching off to UBB.threads, or even UBB.x of late.
so fast en efficient!
UBB.threads blows UBB.Classic out of the water as far as performance is concerned.
search options are much better and amazingly fast. For someone it was the reason for migration. Also he found search capabilities of UBB.Classic poor.
UBB.Threads has a lot more to offer as UBB.Classic and the performance is amazing.
once you take the compression into account (which seems to be around a 90% savings per page), UBB.Threads should almost certainly save quite a bit of bandwidth. (Henri, what did you choose?)
from the software side UBB.Threads now has a powerful tool in the form of templates which you can modify to customize the look and feel of your board. The good news from the POV of a UBB.Classic user is that you'll be able to make it resemble UBB.Classic very closely through a combination of Template and CSS adjustments. Here's a site which most-closely resembles the Classic look IMO: example classic look
we were able to maintain our UBB.Classic look by creating a new stylesheet and altering templates.
UBB.Threads is very fast and highly customizable for both site owner and readers.
functions such as 'past 24' are nice and useful in Classic, but Threads is moving full steam ahead and now that the engine is as fine-tuned as it can get, I think we can expect a lot of improvements with regards to new features as well as the general look & feel of the board.
the "Who is online" feature turned on on UBB.Classic is a very resource intensive process. Also the preformance will be influence by "How many posts per page?", "Are images permitted?", "What UBB.Classic features are enabled?", "Are system wide searches enabled?", etc.

Some disadvantages

is there any way to disable the case-sensitive UBB code? i.e. [ b] ... <> [B]
lots of complaints from users about navigation
UBB.x has more of the look and feel of UBB.classic, but this version isn't for free. Not for free means: infopop is hosting those sites.
somewhat limited and underdeveloped control-panel.
there are numerous features in UBB.Classic that are not in UBB.Threads, and some of them are sorely missed.

Some other remarks we found

UBB.Classic and UBB.Threads are two completely different products with completely different Control Panels)
comparison UBB versions compare UBB.x, UBB.Classic, UBB.Threads

Some very nice examples about personal look of UBB.Thread boards:

Conclusion: with the recent discussions about upgrading this site we see that a great amount of things are possible. Things which were impossible with the UBB.Classic software.
greetings.