I recently installed a used FSwerks GT28R turbo kit on my 2007 ST. I chose Tom to tune it, as I had had previous experience with him before with my SVT focus, and also because his tunes are a pay once, tuning for life deal.
Before I installed the turbo, the car had a cosworth intake manifold, FSwerks CAI and exhaust, and CFM 67mm throttle body. I had installed a wideband and Tom got me re-familiarized with the tuning process as we tuned my car for NA. I had previously bought my X4 tuner from FSwerks, and the tune that came with it was fine, but Tom's tune felt smoother by the end of the initial tuning for NA. (This is not meant to be a bash on FSwerks, I've heard a lot of positive things about their tuner. I bought their SCT X4 and gave my mod list and got a tune; if I was supposed to contact them to fine tune it I wasn't aware.)
When I finally got the turbo installed, Tom was working with me and my tune almost every day. there were a couple days when I wasn't working that we were able to get 4 or 5 datalogs in. He'd send me the next tune, I'd get it datalogged and back to him within an hour, and he'd have another tune back to me in like a half hour. In general he's pretty quick to respond, but as others have stated, he is a one man operation and he's got a family too, so it's unreasonable to expect this kind of speed from him 24/7. Although, I'm pretty sure he put off dinner or a movie with his wife for like an hour when we were on the phone trying to figure out why the car didn't want to start with the second tune.
We did have a few hiccups, we spent a lot of time trying to figure out why my wideband wasn't reading below 13.4 and it ended up being the sensor. replaced that and we were good to go. There were a couple times where there was confusion through the emails, like I wasn't able to explain what I was experiencing in a way that made sense, or I would have to write a book to explain it. I would suggest just giving Tom a call in those cases. it would have saved us a few days if I had been more willing or able to call Tom to clarify simple things.
Now at the end of the tuning process, the car feels fantastic, like it was always meant to have a turbo. I've only filled my tank a few times since the last tune, but I got 27 and 30 MPG on the last two fill ups. As NA I was only getting 25-26 average. More importantly, much more smiles per gallon. I thought this car was fun before, but now it's a blast. I thought I had a taste of forced induction with my Mach 1 and the procharger I had installed on that, but a turbo is a whole different breed. nearly instant power is so fun. No longer need to downshift to pass anyone quickly on the highway.
Tom's process definitely takes longer than your average dyno tune, but what you get is a tune tailored for how you drive your car; not just at WOT, but the rest of the time too. Also, the cost of turbo tuning with Tom is about the same price as a single dyno tuning session with my Mustang. I'm going to have to drop another $500 when I go back to get my Mach 1 tuned again when I do this engine swap and crank up the blower boost, but I'm all set with the Focus if I eventually decide to change things there again.