I just installed the Oxford Heaterz. My advice? Lots of people reported problems with the original controller. However, the free stuff is tempting.
Here's something you have to realise. Putting the grips on is not that big of a deal, but there's things that could go wrong. Especially with the throttle tube etc, I wouldn't risk putting a set on, then having to take it off and replacing, etc.
Here's my review, very fond of them!
Grey Suzuki DL650 ABS K8
SW-M center stand, OEM crash bars, SV racing parts sliders, Scotts stabilizer, DL1000 Seat, ProTaper ATV High, Acerbis Enduro handguards, Oxford Heated Grips, Murphs forkbrace, GIVI D260ST/Euro Shorty with Madstad, RacerATB corrected speedo gauge, Speedstar protectors, Fenda Extenda, Touratech sidestand extender, TomTom Rider 2 on homemade bracket, KLR650 Pegs