I haven't but, I just got my first custom tune from Johan over the weekend (tuned me on a Sunday!) I was extremely pleased on how communicative he was, walked me through (he sent me .doc file and i read up on everything) Installed the tune to the car, drove around like a grandma for some errands and parked it. 2 hours later had to go to the next town, on my way back Lets just say i floored it and my hat flew off to the back seat. Car feels much stronger than ever before. Every tuner is a bit different, who you pick won't matter, What matters is how much more desirable it is to drive the car now.
I'm on his second rev of my tune, I just installed the tune 15 min ago, so far i'm extremely happy with the way things are going. Just have to wait a day or so for my monitors to reset, so i can data log again.
Either will do, can't go wrong really. I went with Johan because I knew more about him through others at the time. He was very pleasant, helpful and I can honestly say my car now drives like a beast! Couldn't say that before even with the 91 CAI canned tune.