I beleive you are right about the size, you also want room for the fuel.... I have a 6oz hopper in front of a 8 oz ,seems to wor well , the tx-timer is set on 6 minutes but seems to be extendable a minute or two.
But I will get a bladder 8oz and loose some weight also! both aft (lead) and from the hopper tank.
It's a very well visible size in the air, and still small in my car.
The speed, hmm no idea I'll pass on that. Angel? But my clubmates gives me hands a wide grins after flights
