Are you talking about resetting your phone to factory under: Settings -> About -> Reset your phone, or doing the Volume Down + Power Button + Camera button for 10 seconds?
nm, I see you meant soft reset. I did a few times on my wife's phone, it would shut off and wouldn't wake with the power button, had to do a soft reset to wake it every time. Ended up exchanging the phone and the new one has been fine since the replacement. I never had to perform a reset while the phone was on but I'm guessing it doesn't matter, either way the issue always came back until we replaced it.