I just bought a new SMC True Spec Premium 85A/90C 4600 mah battery and was doing my "baseline" reading of the battery. I'm OCD. I do a baseline reading of the battery and then do the same after 10 full cycles to track how the battery degrades over time and use. The numbers that you will see WILL NOT be the same as whatever other charger/discharger you use since it seems that manufacturers have their own methods to determine internal resistance (IR). So this is the way that I charge/discharge batteries and I'm sure everyone else has their opinion of what's right for them. I wanted to share quantitatively what it looks like using my equipment.

Charger = Team Orion set at 10 Amps
Discharger = Duratrax ICE at 10 Amps (It's the only one that I know so far that discharges at the full 10 Amps)

Baseline
SMC 4600 85C
mAh: 4612 mah
IR: 27 mOhms
Avg V: 7.45 V

REVTECH 4500 100C
mAh: 4500 mah (weird it came out exact)
IR: 21 mOhms
Avg V: 7.51 V

Ultimate 6000 90C
mAh: 6030 mah
IR: 13 mOhms
Avg V: 7.55 V

Current State of Old Batteries
REVTECH 4500 100C after 30 cycles
mAh: 3621 mah (lost around 900 mah over 30 cycles)
IR: 34 mOhms
Avg V: 7.25 V

Ultimate 6000 90C after 20 cycles
mAh: 5021mah (lost 1000 mah over 20 cycles)
IR: 16 mOhms
Avg V: 7.51 V

So what does this tell me? It tells me that both SMC and REVTECH are not as good as the Turnigy Ultimates. The SMC brand new has an IR that is much higher than the Ultimate even at 20 cycles or the REVTECH. The voltage of the Ultimate is also higher even at 20 cycles.

I paid $33 + $12 shipping for the SMC. Running the car, it does feel "flat" like the REVTECH when compared to the older Ultimate pack. Go figure. Would it get better in time? I'll let you know... But right now, I'm not buying anymore SMC's until I get more data.

Prior to me doing the baselines, I also ran Turnigy Nano-Tech which gave me 18 and 20 IR. But I didn't include them in the above since I didn't have a true baseline for them. I also ran Thunder Powers which gave me 34 IR after about 80 cycles (I don't have an accurate # of cycles for them).

Again, I'm just sharing my results and I have no affiliation with any of these companies. I'm just being OCD with a natural curiosity about these things. I'm sure others can have differing results. But these are mine.

Edit: I got sucked into the marketing and bought the brand spankin new Reedy Zappers. This was $80 shipped from Reedy directly.... go figure... here were the results:

Reedy Zappers 4800 110C 7.6V HV (charged to 8.4V)
mAh: 4099 mah
IR: 17 mOhms
Avg V: 7.51 V

Reedy Zappers 4800 110C 7.6V HV (charged to 8.6V)
mAh: 4466 mah
IR: 17 mOhms
Avg V: 7.56 V

Am I cynical for actually expecting that the mah will fall short? Honestly, I didn't think it would fall THAT short. We're talking 15% short when charged to 8.4V and 7% short when charged to 8.6V. I hope that this will improve after 10 cycles. But we'll see.

I would have thought that the average voltage would be higher. But, of course, it was not much. I highly doubt I would notice a 0.02 or 0.07 V difference when compared to the Ultimate Shorty.

Resistance wise, it looks just about as good as the cheaper batteries. As always, the proof will be in the pudding. I'll let you know once I get it on the track.