Yeah I've got the Q spark in my C4 at the moment and it's perfect for indoors. Really nice combo which as you say Mark runs super cool. Although for some strange reason it stopped working last night. The steering was turning but it wouldn't drive the motor. Minty tried everything to get it back working but no joy unfortunately. Orca have great customer service though so it'll be sorted no worries.
The R10 and vortex 6.5 will be firstly a back up for the Orca and secondly for a B44.1 which I'm hoping to get running by summer time. As you said Ian it will be too hot for indoors but should be great for the outdoor season
