compacts can be good for space limitations but the t8s are cheaper and you can overdrive them and you can switch spectrum at wiil as long as you have the extra bulbs. I have a 65w lights of america fixture with a flourex 6500k bulb and it doesnt seem to put out as much light as a standard t8 2 bulb fixture that costs $20 less. im no expert on any of this but these are just my observations. one other thing is you can get more area coverage with the 4 footers