Enough Voltage?
 

This may be a dumb question, but will a 1527 run the 2,250 watts cont. that it is rated at on 5 or 6s?

Not likely without cooling. That is a lot of continuous power output for an RC.

I guess what i'm really asking is; can it on 5 or 6s, produce the same wattage as it would on say, 10s?

Yes, but the amperage(and heat) will go waaaaaay up...

Generally speaking, yes - as long as the appropriate wind is used for each voltage. (1/2 the kv for double the voltage). A given motor will certainly have its "ideal" voltage and current range, though. The "best" motor for 5s use at the required power output isn't likely the the "best" motor for 10s use at the same power level.