I have driven the Flux and and E-Revo with a brushless motor. Both platforms were run basically in stock forms with no real setup to suspension. The Revo did handle better and in stock form could turn faster, etc. The Savage however felt funnier to drive because of the bash ability of the Savage. Really it kinda depends on what you want to start with. The Savage is the better basher but doesn't do as well at the track. BUT can be made into a great racer. Well the Revo does better at the track but doesn't seem a bashable as the Savage. But can be made in a great basher.
If I where to chose I feel like I would go with the Flux over the Revo. I just in general had better time driving it and with the wheelies and everything its nice to have the toughness of the Savage.