Which is better: the Lenovo ThinkCentre M710q or the Apple - Mac Mini?

I'm looking for a computer to replace my home entertainment computer. I'm only looking at Mini-Computers. I'm not nor have I ever been an Apple guy, but I would consider that for this project. The problem to me appears that I can upgrade the ThinkCentre and I can't upgrade the Mac. However, I've had people tell me that because the Apple OS runs on much lower specs, this would not be necessary. Not only do I want something that can play back movies on my TV, but I want something that can run Plex Server, and Serato Pro.

Also, does anybody have any recommendations about a Mini-Computer from personal experience?

I highly recommend any Apple computer. The Mac Mini will do all you need it to do and with far less problems than any Windows computer.