For a basher, the towerpro MG995 can typically be found for $20. Granted, not the top of the line servo, but definitely strong and pretty quick. I didn't care for the 645MG in my maxx when I had it. Just enough torque to wish I had more.
The MG995 doesn't center really well and it overshoots a bit when going full left/right, but for a basher and with the slop a t-maxx has in it's steering, you may not even notice it. I have one in my jato currently and it's way overpowered.
Even with the jato's built in servo saver tightened, it still overpowers it easily.
Like I said, not the best, but I wouldn't think twice to spend $20 on another just to have a spare servo on hand.
I run decent hitec 985MG's in my rigs too, but those are $70 a piece. Great servo though... would replace all my servos with the 985MG if I had the money to drop on 7 of them... I don't. lol I use them for throttle/brake on my aftershock and my Jammin buggy. They are sealed, fast and strong. Perfect for throttle/brake. A bit overkill for my application, but one less thing to worry about when I'm running in "damp" conditions.