Just thought I'd add in my thoughts.
Firstly I'll just say I've never run any LRP Quantams, or Novaks, so I can't really comment on the speedos. I have run a v7.1 though, and that was a lovely speedo, never had any problems with it, and I did treat it pretty rough (running it in fully wet conditions etc).
However, I have heard a number of stories from fellow club racers having problems with their QC2's (and dominator evo's), in that they started smoking for no apparent reason.... someone actually blew one up last week, in the final round of Q, he got to within about 30secs of the finish, and the car stopped. Boy did it stink....
Also another one of my fellow club racers has a GT7, which did break, but he sent it back to novak to get repaired, and from what I can gather it was pretty quickly dealt with.
I personally haven't had any probelms with LRP returns, my Pulsar comp charger blew a FET recently, and being about a month and a bit old I sent it back to Helger distribution over here in the UK, and I got a replacement send back within 2 weeks, so quite pleased.
Currently I'm running a MRT VX Pro, and it is a wicked little speedo, a little larger than most, but the corrally connectors making removing a motor easy (no need to de-solder wires), and it is wonderfully tuneable (14 odd throttle profiles, 14 odd brake profiles, launch control profiles etc etc.) PLUS it IS 100% water-proof (well at least to my knowledge, haven't dared imerse it in a glass of water yet...
), unlike so-called w/proof LRP's.....
I actually picked up mine unused second hand, and have been very happy with it, and would highly recommend it. It will probably be cheaper than the LRP or Novaks too.
p.s. don't get a mTroniks Cirrus, I've seen three of thoose blow up on one guys car over the past 2 months.... not pretty.