I've got the 151 on my IVA-D300. Reception is to be expected when you're driving around. Just imagine watching tv with rabbit ears....then start moving the antenna around while you watch. I would say not to expect anything spectacular. I enjoy it for the simple fact that I can get news stations and watch some tv if I'm parked and trying to burn some time.
Channel 4 and 5 typically are bad reception. For the most part, I don't even pick up channel 4....and hardly pick up channel 5. What's really nice about the Alpine tuner is that it integrates into the touchscreen on the alpine head unit. If you're going to watch while driving, you're going to have to change the MX mode to something with less bass. The reception "pops" will bug the sheit out of you.
If you'd like, I can see about snapping some pics of the reception quality sometime.