Currently flying with the 3500 which I reckon is a fantastic bit of kit. I realise you're asking about the 3308, but the 3500 could well be worth considering. LED does make a difference. Some of our guys have trouble with it initialising... but in my experience that's because they're a little rip, **** & bust after start-up. My habit is to just take your time -it only takes a minute or 2 for it to initialise after power-on. Best just to leave the instrument untouched until fully up too -setting it too early seems to extend the time taken. We've had 1 AHRS fall over too... possibly a consequence of the strips we work. It can be a fairly physical environment. I believe Sandel have a "ruggedised" AHRS available now too, that would address any concerns there.