Josh your Spektrum radio will work fin with the lipo. Your servo may not like it. Which one do you have? I know Larry has used a JR with no problem. The KO servos are fine also. I do not know about the Hitec servos.
Steve the way it sounds with the Advance Electronics unit that has come out. All the other esc manis are looking at how to get more out of the cars. Both TC and single cell. Mamba has a 1 cell version that they are making a limited run on. I hear these are very close to the AE speedo in single cell.
The Tekin of course is a good one that has potential. I have heard of a fourth coming new speedo that Drew knows a little something about
I am sure these will be good also.
Novak has their new Kenetic coming out. I am not sure ho that one will stack up.
LRP has a SXX stock spec coming out. This is different from the SPX stock spec.
The Mamba Max Pro si suppose to be up to and some better than the Tekin as far as speed in TC. And this sells for like $130
Brushless has really caused a problem in on road with the speedo timing issue. So many choices and I know I would not want to be left behind with the wrong choice.