I use second hand speedies all the time, the way i see it, either way there is always a chance a speedie is gunna fail

I have second hand
2 x QC2s
1 x GTX
1 x Sphere Competition 2007

I think ive heard of a couple of sphere's going up in smoke but both times i believe the user plugged them in back to front (although the sphere is meant to have reverse polarity protection so it shouldnt have failed in the first place ).

I have seen GTBs go up in non mod cars. The mod touring cars definitely pushes electronics to the limit, however with the rating of the GTB it shouldnt be pushed by a motor of 10.5/19T or less.

But to me there are a lot more spheres around than GTBs so if reliablity were an issue you would see a lot more failing.

Anyway thats my opinion from what i have seen around **SHRUG**