You're a little late to the game, but I understand completely. However, it was my belief (perhaps wrong) that more tuners use PC5's and its software than the HD race tuner I currently have. Therefore, it's easier to find someone to tune my bike. I was also told the the Pc5 software is a little more advanced and, therefore, it takes less time to tune. That's all.
'Had 107/119 on the dyno sheet when the '09 SERG had the SE Stage III Kit SEPST... (sea level / 93 octane / cool day) I really didn't care about the numbers, just the drivability (which was good after a full day of dyno to get a flat spot out).
When we went to 117/DD7 I went with the PC-V / Auto with a spot-on Base Map, with minimal tweeking on my part. (wanted to get out of the dyno business) The bike runs fine everywhere / every time, averaging 40+ MPG 2-up/loaded at Interstate+ speeds, 35-38 around town, with 8.5k miles so far. Never a ping from sea level to > 6k ft. 2-up / loaded, this Summer.
Other than a mild curiosity to see what the #s actually are, the 117 won't see a drum anytime soon.
There is the capability to adjust the timing with the PC-V but the bike runs so good so I don't play with it. 'Don't want to fix it, 'cause it ain't broke...
I'm in a minority here, as I like the PC-V/Auto and don't feel the need to dyno the bike to have it running properly.
The PC-V / Auto does give the flexibility to "re-tune" for component changes without any more Dyno$$.
The one thing that the PC-V doesn't have is Throttle Blade Control (you may or may not want it depending on your bike, on some bikes TBC can show an improvement, some bikes it makes no difference)
I agree with the posts here, the "Tuner" makes the real difference, not necessarily the Device.
I also agree with you that there are probably more PC-Vs out there than HD race tuners, and more / better canned maps available for the PC-V.
Even though I am a fan of the PC-V/Auto, you should be able to find a Tuner in your area to have the SEPST do what you want it to do.