A couple more things worth noting:

1) While both my 3S and 2S packs produce about the same amount of work in Wh( watt hours), the 3S pack weighs 36g more which actually improved the performance of my 4WD SCT on the track, I would improve my fast lap by 0.3 sec on a 40 sec hot lap. I do want to caution that there is a point of diminishing return, I also have noticed that my truck tends to bottom out a little more easily now and I probably need to add some more pack in my shocks to accommodate the extra weight. This is a very recent change I made and will require me to adjust my car setup accordingly as I monitor my lap times to make sure I'm not making anything worse.

2) The 2S pack was a 100C pack which cost about $150, definitely a very high quality pack is necessary for 2S when pulling extremely high current you need a higher C rating on the battery to sustain that much load. When I switched to 3S I was able to buy 50C pack that was only $50 where it's not necessary to have a high C rated pack when you are pulling less current. I did check my battery pack this last week and temps remained the same ambient temp at around 100°F after each run, ESC was around 115°F as well which tells me that my gearing was also in the optimal range, my lap times are right on par with most 4S powered 1/8 Buggies as well at the local club.