I would call the 9T a little above mediocre. It posts about the same K/D as some of the most popular 109s, around .98 give or take. I dont really think the better sticks fly it much, as compared to the 109s. I believe a lot of the newer sticks see the big gun and take it up for that, and just for that.
But it has a narrow scope of use, "as did many aircraft in the tactical minded SAF". Your not going to take the 9T up furballing, or take it cross country full of gas. It doesnt have the range, even more so, doesnt have the ammo load. It is strictly a tactical aircraft that can hold its own against other fighters as long as you arent ganed so much. It has Mossie speed. IL2 firepower "almost". It will out turn many of the jabos in the game. It is a surprisingly good stall fighter as long as you use trim correctly. It can take out a couple of the tanks at need. Its deadly against PT boats and all the other GVs.
Most furballers wont ever like it cause they mostly "furball". Or they mostly simply dog fight other fighters. I think most of them would be better served with the 20 to 30 eny German set. As a dogfighter "mediocre", or, "average" would probably fit.
But the game is more then just a furballers game. look at the airplane in that light to see its strengths.