I've had Gregg come out and calibrate two sets for me in the past few months - a Hitachi 57S500 CRT RPTV and a new Samsung 67A750 DLP. In both cases, I found Gregg to be exceedingly professional as well as very personable. He is very good at explaining what he's doing and why he's doing it, as well as freely answering any questions I had for him, no matter how dumb.
The first calibration he did for me was on my Hitachi CRT RPTV. He gave me plenty of advance notice, as well as a nice list of pre-visit housekeeping tasks that would help the process go smoother, and was very responsive to questions I emailed him prior to his arrival. He showed up right when I was expecting him, unpacked his equipment, and got started - removing the glare screen and restacking it, doing a full cleaning of my optics, and once that was done and everything was reassembled, getting out his image analysis equipment and really getting to work.
He spent probably about an hour in the service menu just doing grayscale tweaks, and after that he spent another hour getting my convergence and geometry in good shape. After that, he checked every one of my inputs to make sure I had the correct user settings, and finished off by showing me some reference material and pointing out the improvements he had made - which he really didn't have to do at all, as the image was so much better than what I'd been used to I couldn't believe I was watching the same TV!
A few months afterward, I unfortunately messed up my screen and decided I needed a new set (hence why I joined AVS). I actually sent Gregg a few emails asking him for his opinion on some of the sets I was looking at, and to my surprise, Gregg was very responsive and gave me great advice. After that, I knew I wanted to have him come out and calibrate whatever new set I got - which turned out to be the Samsung DLP, which he came by and calibrated this past Monday.
Knowing the drill at this point, I spent a pleasurable two hours watching Gregg work (there was no screen to modify, lenses to clean, or convergence to fix, after all) and am quite happy with the job he did. There wasn't quite the WOW factor as when he fixed up my Hitachi - one of the reasons I got the Sammy was because of its reputation for good OOB performance - but there were definitely some improvements to be made, and it was nice to have him check all of my input devices to make sure their settings were correct.
I highly recommend Gregg Loewen - he's an incredibly knowledgeable and skilled calibrator who's also a good guy to hang around with for a few hours. I'm attaching the pre- and post-calibration reports he emailed me after each visit, so everybody can see for themselves what he was able to do.
57S500_pre.pdf 85.1396484375k . file
57S500_post.pdf 82.7607421875k . file
67A750_pre.pdf 123.8740234375k . file
67A750_post.pdf 126.7451171875k . file