I just received mine, an Akiak, about 3 weeks ago, so probably not much of a review. Plus, I am not a full-on Greenland convert, I still use Werners much of the time. I can say that the Gearlab build quality is superb. There are no flaws, blems or other imperfections. The push button joint is excellent and tight, but not too tight, if that makes sense. I haven't tried removing the tips, so no comment on how that works or its ease.
As far as paddling and on the water feel goes, the only other Greenland paddle I have used/owned is a wooden Northpoint made in Bellingham, WA. The Northpoint feels better to me, this is more of a feeling based on wood versus carbon, though. I have always preferred wood over composite when it comes to paddles, even in whitewater. The Akiak is shoulderless whereas the Northpoint is shouldered, I haven't really noticed much of a difference as far as that goes. The main reason I bought the Gearlab was for the two piece design.
I bought mine on ebay for $300, no tax and free shipping. There was four of them at various sizes and a few Nukilik at the time. Just checked before posting this and the ad is gone. However, if interested you may want to call Naples Outfitters, Naples, FL. While the ebay ad did not expressly say Naples Outfitters, I'm pretty sure the paddle came from them.