What do you want from this deck??? Is it just to power speakers and for occasional listening or do you want it to be the brain for a future system??? The Pioneer does have a lot more features than the Alpine, so if you decide on it, then it'll be fine later on for adding amps and so forth.
Personally, I do not like the looks of these 1.5 din sized decks. I'd rather buy a regular 1 din deck and get a mounting kit. But if it were the Alpine 1.5 din retractable face deck, then that's a different story.