Planetmars and Matt52 hit the nail on the head. This was BC's best trade ever, and was a huge win for the Raptors. With an imminent rebuild looming I see Gay being dealt, but I'm ecstatic we have a player like Gay as an asset to trade. We converted several low value assets into a high value asset. As long as you don't get too attached to players (looking at you BC), then dealing low value for high value is always a good idea, even if it doesn't make a ton of roster sense at the time. The roster can always be adjusted in subsequent moves (one of BC's biggest failures was thinking one move was enough).
We have people in the forums saying they wouldn't deal Gay for the #1 or #2 pick in this years draft. That's how high his value is perceived. It'd be a cold day in hell before anyone talks about Ed Davis like that.