How good (or bad) is the Android tablet ecosystem these days?

Early this year I decided to make the tablet plunge and went with an iPad 4. The reason I originally went with it was due to the much more expansive app ecosystem for tablets.

Since then I've continually ran into annoyances that make me regret not going Android. For instance, I want to load up my iPad with my own music, movies, or TV shows that I have on my PC. From what I can tell, there is absolutely no way to just drag this stuff onto it and access it. It looks like I need to go through iTunes for everything? Plex works but I'm not always on my WiFi.

So how bad is the Android tablet ecosystem? I am deciding whether to sell my iPad 4 now, get as much as I can for it and jump to the refreshed Nexus 7 or 10 later this year.