Jaxx, if the local tuner uses eitehr the SERT (actually, a SEPST) or PC, I would go SESPT. Its a HD product and a lot of dealers that tune use it. So, if you find yourself on the open road and have a issue, you are more likely to find a skilled tech at a dealer that is familiar with the SEPST, over a PC.
That said, I have (had) a RevPerf P-EMS on my 07 RG, sold last month. I had a TMax and then went to SEPST, then P-EMS in October. The product does what they say it does. It provides a great running bike and no messing around with maps and data runs and dyno and all that. Install is, start the bike and let it fully warm up for 5-w0 minutes, and the bike is tuned. Done. No more mess.
Going from the SEPST to the P-EMS, I had some low RPM stumble I couldnt tune out. Off idle RPMs when egine was wamred up was a PITA. I spent weeks playing with cells and doing Smart Tunes and keep futzing with cells. I finally gave up and got a P-EMS.
The stumbles and shakes went away and the engine was noticeably smoother running. It was hard to understand why, but all I know is my problems were cured by this product.
Also, after about 300 miles of riding, I never had any issues with it. It still ran great and very smooth. The guy I sold the bike to was pretty happy to get a great running bike, he figured he would have to get it tuned when he got it. I live at 6000 feet, he lived at 200 feet, above sea level. I built the motor to run well as all altitudes, so no surprise it ran great for him.
Anyhow, maybe the P-EMS leaves a little performance on the table, but I dont care. The bike was strong, smooth and no issues at all, so what more do you want? I have had bikes that didnt run as well that wee tuned professionally. Probably never again in my lifetime.
Hope this helps someone.
Dennis