That's what I did. I knew of the problems before buying, and swore I wouldn't buy a crippled version of the game on PSN. However, I didn't have an iOS, WebOS, or Android device, so when the game went on sale, I said "What the heck" and pulled the trigger on a purchase.
The game is fun, but the slowdown and frame rate degradation on some levels is truly jarring.
I understand the new version is under a different publisher (Rovio itself, rather than Chillingo), but it doesn't look like they added any new content to warrant a repurchase. They just fixed the slowdown and glitches which so many people complained about on various online channels. The actual developer of the Minis version (Abstraction Games) was apparently aware of the issue, patched it up to 1.03 while it was still under Chillingo's publishing banner, but these problems weren't resolved. Apparently, they just gave up on trying to "fix" the problem...until now, when it got republished and fixed it after all...for a price!
Those who bought the earlier version deserve a free update. Anything less is unacceptable at this point.