If you were flat-@ss broke (like me) and you were buying a CD receiver
out of those two...blaupunkt for sure...especially if you ever listen to the radio...blaupunkt is known for very good FM reception..
GO ALPINE IF YOU CAN.
but if you are not wanting to spend more than $200, can't find an Alpine you like, and you are lookin on crutchfield....there are some really nice Clarion decks...they make quality stuff..and they have decks that have the twisty volume knob you're wantin...there is also a nice Sony deckCDX-CA700X..which would sound real nice...they are known for not so good radio(not as good as that blaupunkt anyway)...nice CD sound...almost no skipping in their newer decks....and buttons that fall off occasionally..
personally I would stay away from AIWA junk...