We got there early and A/C was quite strong, even too cold near the front. Perhaps it has to do with location.
About the sound, if you are in the first 5 rows, it doesn't matter too much what size is the venue since you mostly get the sound from the stage. The mix there wasn't perfect like all venues (low vocals), but it was OK. Also the view is more than fine from there. So overall Echostage isn't bad.