I had just recently received a Nyko TS unit. It made a 30 degree difference in temp on my xbox. I checked the air temp coming out of the fans before and after the intercooler with a calibrated thermometer. The TS has it's own power supply, so it does not use the xbox360's power whatsoever. Installation and removal makes no marks or warranty voids anywhere on the console.
Some of the older model intercoolers, I know caused problems, but I can not see a forseeable problem with the TS unit I have. A fellow forum member did a nice write up on modded TS units, with documentation to back up the intercoolers positive impact on the xbox. Long read, but here's a link to that thread, if you get bored. lol
http://forums.xbox.com/26271433/ShowPost.aspx