I have the Hydro Farm 4 ft. rails (I also sell hydro Farm products to the MMJ community at 25% to 30% discounts; 4U2), and I like them especially for the price. I see what and why people buy and what gets returned is the best analysis. I also use their cheapest reflector (Wing) which weighs only a pound or so (actually, the socket and cord weigh the most). Works fine although they get out of sync. I have 8- with 600W HPS and run them about 14" from the tops. 144 plants in a 13'8" square but that has a perimeter for those pesky branches. The light rail (4 ft.) actually covers a 6 ft. path from end to end, so my effective square is actually 12 X 12. 1 module/sq.ft @ 33.3 W/sq. ft. The light is sufficient this way rather than using 1,000W stationary. I also just buy the ballast components and wire myself. one doesn't save much, but you get American Transformers that will way outlast the cheap "overseas" made products. Same goes with the rails, but Hydro Farm's is made for them in China.
Craig's list usually has at least 4-5 hydro/reflector/ballast/fans, etc. Daily new entries too, because there are so many people that go and buy a High Times, read an article and decide that a Hydro grow would be 'so easy, I can do that". They buy all this stuff and end up abandoning it all due to the complexities we have all come to know and (love)... They have the money but lack commitment and discipline. Nothing proves more of the commitment than having to drop what you are doing and go and deal with a problem @ 3 in the morning. Keep up the good stuff here; thanks to everyone especially the people that put a lot of work into their posts...