You don't think a guy whose range is 2-3 WAR is someone we can put in CF long-term? That's basically Mallex's ceiling.
Exactly! Yes, I think a 2-3 WAR guy in CF who is controlled for 4 years is exactly the type of player a team would covet. However, the Braves won't be good for 1-2 of those 4 years. They also have a very similar player in Mallex that can probably produce 2 WAR in CF and is controlled for 6 years.
All this arguing boils down to my opinion on the matter being this:
If a "win now" team values Inciarte as a 3+ WAR guy in CF for the next 4 years, and is willing to pay accordingly, trade him. If teams value him as a ~2 WAR guy with platoon issues, keep him until Mallex has proven more in AAA and/or the MLB level.
To me, Soler plus another decent piece is a clear win for the Braves. Getting 1 top 50 guy, or 2 top 100 guys is a clear win for the Braves. Anything less and it doesn't make sense to trade him.