I own a Stampede and I was wondering if anyone could give me their opinion on a Reedy Neo 2T/Sphere combo or Lehner 4200 with a BK warrior 7018? I've got the specs for the Lehner but Reedy and seems to be secretive about their specs. Other questions are:
1. Can I run lipo's on both?
2. How many volts (high and low) on each setup?
3. Which setup has the best runtime?
Any answers would be helpful. Thanks.

Why do you want something that fancy in a Stampede? I'm not trying to be a jerk, just save you a little cash maybe. I just sold two used but perfect Novak 4300s, they had been used for many applications and they were still in great condition and I never had a single problem...

I figured someone would ask that question. My reasons are many:
1. I'd like to buy a good setup that I can use in other 1/10th scale cars as progress in the hobby.
2. Those combos are some of the least expensive brushless setups out there ($234.00 for the Reedy/Sphere and ($229.00 for the lehner/BK.)
3. I don't want to mess with the maintenance on brushed motors.
4. The Stampede is one of the most durable backyard bashers ever made and it does very well with the abuse it will take from a brushless system. Go visit www.swami-rc.com He has some great videos of the Stampede and Rustler.

The volts/cell specs on each should be available from the manufacturer. Not sure on runtime, it depends on the motor... just remember, generally faster means less run time.

Personally, I would go with the LRP (or better yet the Novak). It will be much easier to get service on the LRP. But I have found that Novak has much better warranty/service then LRP.

Thanks for the input. I looked at the GTB but I was wondering why they made it to only take 4-6 cells?
Another question about motors in general:
Are the brushless motors limited by RPM only or are they voltage limited also?

RPM is a function of voltage... more volts more RPM. All motors that I know have a voltage limit.

4-6 cells is what most racers use, and also what most hobby guys are currently using... LiPo really hasn't caught on that much just yet... but anyway, I don't work for Novak so couldn't say what actualy drives their choice like this. However I really don't think there should be any problem running a two cell LiPo pack with the GTB...

The voltage limit is more likely a issue with the controler then the motors... At least when you consider reasonable voltages... There really is little reason to run more then 7.4 volts in a 10th scale racer type vehicle... Maybe in some big monster trucks, but not in your typical racer.

There are no RPM limts to brushless, unless the user chooses that option... RPM is a function of the motor design and the input voltage... The motors themselves don't have any sort of governer/limiter... they may however get too hot, etc... if you use to high a voltage...