From 3300s you can probably expect anywhere from 8-15+mins.

Matched packs can make a big difference. It can give you better run times and better performance. I won't go into detail but they are better and worth it in my OPinion.

All batteries should be prepped charged before they are charged fast. What I mean is new batteries should be charged for C/10 (capacity divided by 10) for the first 3 charges then you can fast charge them. This will help reach full capacity when you do c/10 for the first 3 charges for a new battery.

Fast charging, you can charge them at different rates depending on Ni-Cad or NiMH. It is recommended that if you use Ni-Cads to fast charge you should do it at 2 times the capacity and for NiMH 1 times the capacity. Which relates to about 30min to an hour.

Well you can charge them at higher rates like 3-4 times their capacity but that is a bit fast, and its at your discretion which is about 15-20 mins. With a good charger and good batteries they can last you years.

Isphius, Does your blackfoot run longer running two packs parallel than just one pack of the same capacity? I haven't tried but wanted to know. Of course I know it helps to have similar packs when you do run them parallel. On average how long does your parallel packs last you vs a single pack?

I have seen people use Sub-C batteries for the receiver but I think that is a bit too much weight and too big for a receiver battery. I have made my own 6v receiver battery with 2000mah AA NiMH. If you don't care about weight or size might as well use D batteries with 8000mah capacity!! hehe!