I have posted problems with OD 2.0 Plus in other threads. I'll post them here as well in hopes these issues finally get resolved.
1. The biggest issue I have right now is that OD appears to cause my explorer.exe to start using 20% and turning the whole windows UI into a sluggish crawl until restart. When I dont use OD, I have no problems. When I do use OD, I dont typically have problems until I've been running a game for a while (probably something coupled with full screen mode). The only commonality I've found to this behavior was whether or not I have OD active.
2. Tabbed dock is horribly buggy. It takes nearly 2 minutes longer for the tabbed dock to finally show up after the quicklaunch dock has already appeared. Then, when the tabbed dock is up, often times it will lose things like reserved edge of screen or being able to stay on top of other windows until it's manually selected. Sometimes it forgets which monitor edge it was supposed to be docked to. Beyond that, it's sluggish.
3. The quick launch dock isn't without it's problems. Sometimes it "pokes through" games. Sadly, this is almost always a Stardock game (demigod, elemental, and even sins all have issues with the quick launch dock). I've very very rarely had issues with any other developers games.
4. The widgets can be problematic at times, especially anything that needs to phone home for information like weather.
5. Not really a bug, but there isn't a good, explicit way to "save" a full setup/configuration. I'd like all my colors to match my windows taskbar and keep things in the placement when I move things over to a new computer. I've found that transferring the OD folders as a whole doesn't really work and I'm still forced to start over from scratch again.
Anyway, performance and software conflicts are my biggest gripe with OD. Otherwise, I love the program. It's something microsoft should really have implemented a decade ago as a standard. But those issues really make it difficult for me to continue loving the product and the company that makes it.