Performance of Mac mini as a server - doing some research, need some advice

Hi everyone -

I am looking into buying a Mac mini to use as a dedicated Plex server. Was wondering if anyone is using the current low end model (1.4GHz Intel Core i5 Dual-Core, 4GB of RAM
500GB 5400 rpm HD), and if so how it performs serving to an Apple TV?

I'm not opposed to getting the next model up, but if the low end model works without any lag I figure I'd save some money, as I will be buying this STRICTLY as a plex server.

Thanks,

Jamie