difference in lighting

Im getting 4 lights for my XJ light rack. I Im looking at KC for the lights, Im looking at a long range 6" slimlite @ 130W. . or a long range 5"x7" 100W systems. My question is is there a big difference between 130W vs 100W? and does square or round make a difference?

I use a couple of KC clones, with 150 watt bulbs, there was a noticeable light ring. Can´t really see needing any more light. Though when I had a couple of hundred watt fogs on (4x8 rectangular Hella), they did do a better job up close.
Remember watts divided by volts, equals amps.
Most of it has to do with the quality and engineering of the refector. But bigger bulbs, usually makes up for poor engineering.

If you are going to use the lights durring the winter i wouldn't use any larger than 100W i have seen many 130w and 150w bulbs crack the glass form all of the heat and the cold around them.

Fenton Beech

with everything being equal, a round reflector will produce more light then a square reflector.