Currently using 3.3.0 on touch and mini
Never failed to get improved performance.
Consider the forum threads with "problems" are the posts by those who experience "problems".
These are the exceptions not the general experience.
A handfull of users have issues (most caused by the irregular/bad ebooks in their libraries) or personal wish lists based on their peculiar expectations.
Dozens have problems and a few post on the forum.
For others (tens or hundreds of) thousands, it just works and gets better with every update.
Is there ever perfection and no risk while alive?
No.