I thought this deal was pretty close when I looked at it at first.
Ryan Braun is a top-10 bat for fantasy baseball. The upgrade from him to Brandon Phillips is HUGE. The only way you can compare it is if you very heavily weigh 2B over OF for position scarcity. Vazquez is very consistant and strikes out 200 guys a year...and now he is in the NL. Right now I think he is worth as much as, if not more than, Gallardo. He is just not prooven enough to justify you not getting Braun. Snider is a good keeper for a different kind of league but your keepers wont allow you to keep him anyway.
The benefit for this season is just too huge to not take this trade.
If you do take it your 10 keepers will be muuch better with an additional top-10 player(who is young as hell btw).