Well, as I said, I'm repeating what I've been told by credible people and my ESC/ motor manufacturer directly. I might be wrong (it's been know to happen

). But I've read of people clocking 50, 60 and even 70 amp draws using brushless motors of this capacity (about in the 4.5-6.5 range). That's borderline for a 20C 3200 mah pack. I've also read of people running these types of motors in 4wd with 3000 ish Lipos and measuring temps in the 140-160 ºF range (which Lipo manufacturers say is not good for long term durability). Last weekend, I personally saw a guy running a 3200 mah pack (in 2wd open) pull the pack from his car in a hurry because it was swollen to 1.5 times it's size and was really hot (then again, It might not have been current draw that caused this; who knows).
For further information, my packs are not hard case. So I am really feeling the temp of the cells, not of the plastic case protecting the cells and which is certainly cooler than the internals. My packs hardly get warm.
All this to say, that this is what I've been told, have read and have witnessed myself. And it's what pushed me to getting bigger packs despite me not needing them to complete a 5 minute race (I want my Lipos to last). I'm still very new to the brushless/ Lipo game and could very well be wrong, despite the fact I find my (or rather the manufacturers) reasoning makes sense.
And in the end, if you are using the 3200s and they are staying cool enough, and giving you enough power, well that's what counts!

Have any of you compared back to back the same buggy/ setup with 3200s vs a stronger rated pack? I've not, but know someone who claims he can feel a considerable difference.
If you feel this reasoning is flawed, please by all means correct me. I'd gladly learn what I'm wrong about here and gain in knowledge while I'm at it. That's how we learn.
Cheers!