Enclosed ballasts, good or bad?

I have been shopping around for HPS lights and noticed that some complete systems ive been seeing have the ballast built into the reflector. Wasnt sure if something like this is better for space or dangerous with heat inside of a cab or tent. Anyone have experience with these?

When given a choice it's always better to have that heat outside the cabinet. You can turn any light into a remote ballasted one though, as long as you don't get too crazy on the cable length. (If you aren't paranoid about a little wiring.)

There are cheap lights that are already modded to be remote ballast though if you don't want to modify a cheaper one. Check out this and this:

http://www.htgsupply.com/growlights.asp?categoryID=1&subcategoryID=155&typeID=55

http://cgi.ebay.com/400w-HPS-COOL-TUBE-GROW-LIGHT-400-watt-Sodium-Cooltube_W0QQitemZ180127387721QQcmdZViewItemQQptZHydroponics_Seed_Starting?_trksid=p3286.m20.l1116

Both are from the same company...