Lighthound is in the Houston area. they are one of my favorite dealers. I lived in houston for a year in 2004, but this was before CPF :wave:
the turbo models have tactical interface. you have 2 user programmed modes, and can set either one from the 8 different modes available. programming it will take less than 30 seconds.
regular interface, you have all 8 modes availible all the time. with bezel/head tighten it turns on MAX. give the switch a tap, or click and it goes strobe. with head loose, it comes on moonlight mode, and with each tap or click of the switch, it turns to low, medium, high, SOS, and beacon.
the tailcaps are also different. the turbo and tactical models have a protruding switch. while the regular has a flat reverse clicky, which allows tailstanding. also the turbo tailcap is beefier.
great thing about the quarks are you can mix, and match parts, just becareful with the heads. there are 2 voltage level range heads.
eneloops are the best rechargeable options. energizer lithium AA are the best non-rechargeable option.