...More to the point with what I'm trying to get at, being ignorant on the subject myself I'd be interested in hearing what features drove people towards, say, a Pyle system like you linked to.
I've used a couple of systems that look /similar to/ what you linked to, but they were not exactly name brand and didn't work out for one reason or another. The failing point for me was the speakers more than anything else. They'd break in some fashion or another.
If you're looking at playing with something more or less to experiment before diving in, you might search for 'Mini Amp' on Ebay. You can get those things pretty damn cheap.