Hey diffused,
The biggest thing you can do to improve PT is disable the thumbnails. They're going to cause 99% of the issues (which are themselves usually caused by memory issues).
Other than that, while there have been a lot of new features and they'll always introduce bugs, none of the new stuff should impact performance at all (other than the aforementioned thumbnail stuff). Actually, as PodTrapper ages I'm in generally pulling out more code than I'm adding (or at least close to it), and refactoring to make it more reliable.
So, in the end, you should get both more features and more reliability (at least when the features calm down
).
Finally, after having said all that, you can definitely grab older versions, but pretty much all of them have a bug here or there. Let me know if there's a specific version you want to go back to (1.8.6 and 1.7.2 are the only ones I'd recommend).
-Marcus