[jsr]

Most everyone will advise against it, but most also have never tested it out and continue to advise against it via heard word. That's fine and if you want to stay cautious, that's good.
I'm one that has no problem running 3s on my truggy. No batteries, my truggy weighs about 7lbs. It's really not that heavy of a truck and I don't have any fancy CF parts either to lighten it up. I don't run a single 3s pack, but 2x3s packs in parallel. Each pack is rated for 90A, so total of 180A capable (supposedly). On 3s with my gearing, my truggy hits about 40mph. I've bashed and run at the track with zero problems on 2x3s packs. On an 80F day at the track, my ESC was 80-90F, my motor was 90-100F, and my batts were 100F.
I've tried running single 3s packs a few times to see what happens (and I really wanted to get some runtime in and was impatient) and 2 of the packs had 1 cell die (so 3s became 2s). No puffing. Just a dead cell. Need to open the packs up and either make another 3s out of them or make a 4s pack.

Is it the best scenario? No. It's true that it pulls more current. Less current is better.

Is it a setup that can run with no problems and everything stays cool? YES!!!

In case you're interested to know, my BL setup is an EZRun 150A ESC and 3674 motor. I also run on 4s. Not a super efficient, high dollar setup. Yet it still runs great and allows me to pass nitros at the track and out jump them on the jumps that don't have a lot of runway to pick up speed.