I have Quantum's and V12's, and I have never had a problem with any of them. The only reason I could see that they would be a problem is caused by user error.
Once the smoke comes out, you can not put it back in though!
The Novak is a good speed control also, I have nothing bad to say about them, I just do not like how big they are.
As far as a servo, I feel the JR Racing Z8450 is the best servo on the market by far!
By the way, I have a JR Racing R-1 PCM radio for sale, it was my personal radio so it was very well taken care of. I have 1 FM reciever for it, and atleast 4 Z-PCM recievers for it as well. A Orion battery, and a brand new dry cell holder as well. I also have the JR case for it, the case has some dings, but nothing too bad.
(Sorry if this is the wrong place for this, But I would rather give this deal to an Xray driver!) hehehe