It is really tricky to choose a transistor.
I used to work with Pre-Amplifiers and sometimes,the amplifier did not turn on instantaneously and made a sizzling sound.We tried to find out reasons,but could not find any possible reasons.Anyhow,after about 1 minute,the sound started to come out of the loud speakers.
After consultation with the manufacturer of the amplifier modules and subsequent tests,we came to a conclusion that if the amplifier modules were changed while they were charging or discharging,it had an adverse affect on the transistor.The transistor went into a thermal runaway and eventually died when the pre-amplifier stopped working.
Transistor is an important aspect in designing so choose the one which is free of flaws.In other words,choose a transistor on which,the whole circuits failure would not depend.