Maybe before deciding between the PCs and the Mac you should decide what OS and apps you're planning on running, that should make it easy to narrow down the rest of the options.

Hybrid SSDs and real SSDs are not the same thing, the former will be slightly faster than a mechanic drive but an SSD will absolutely smoke it, however, all SSDs are not created equal. The list does not mention which brand/model is used, and there are big differences. And yes, I'd opt for the SSD, they're that good.

I'm not too big on macs so the Alienware would be a snap call for me.