I can comment on the W900. I have an AVIC Z1, INA-W900, and now an AVIC Z130BT. I originally bought the 900 because I wasn't happy with Pioneer's interface on the Z1, in hindsight I should have bought the Z110(current model at the time). I HATE the Alpine unit. I'm not hating for the sake of hating, I used to be pro-alpine everything but they've really gone downhill lately. I'll touch on each of your points specifically so I don't just end up ranting about it.
1. Nav has 6m POI's vs. 12m in the Pioneer - I don't really use POI's, but I find even the Pioneer lacking in my area, so I can onl