This is an interesting thread and the subject always "stirs the pot" a bunch.
A couple of years ago a friend and I were at a bar listening to a writer for a well known "slick" pontificate on the dangers of porting and brakes. He finally had to admit that he had never dealt with any on a handgun. But he never changed his very vocal comments. We all had another drink and parted friends.
I had my first handgun Mag-Na-Ported in '82 - a 2 1/2" Smith #66. It worked so well that I followed up with the 4" #66 duty gun and a 3" #57(41 mag). Shortly after that I had my ASP Mag-Na-Ported and when I got a Freedom Arms # 83 4 3/4" 454, I had Mag-Na-Port put three ports in it (one on either side of the front night sight and one right behind it). Add a Glock #30 with night sights to the Mag-Na-Ported list today.
Back then we had to qualify with what we carried and that included both day and night firing.
I still remember the first time that we had to do that - I was really anxious about it due to the comments that I had read.
However, the anticipation was the worst part - I shot very well with both the Mag-Na-Ported ASP 9MM and the 4" Smith #66 with issue 158gr 357 ammo. Choose your ammo very carefully if you are doing nightfiring whether you have a ported gun or not.
The only gas and powder particle damage I have personally encountered was self inflicted when I absentmindedly extended a finger on my left hand (like a dumbass) in a two hand grip with the 454. I am very lucky in that I didn't lose any finger but did I did embed some powder particles in it (just a reminder to be careful in the future). Fortunately a home remedy drew it right out!
That was from the barrel/cylinder gap!
Your mileage may vary!
Dave