I have only played with the voltage a little bit. Mostly I just found a good spot and left it there. I'm about 1/2 way between the yellow and red. Running on a boge 2.7ohm carto with peppermint juice.
A few observations:
It would be nice if the connection was just a wee bit taller, to fit an ego mega atty. It does look a little silly on there with the adapter, because there is a gap before the big flare of the bottom of the ego atty. I'm going to use my ego megas anyway, because I have 7, and I don't need that many for backups.
The purple is a really nice color. Under the reflection of a light, it's almost pink. A blue-purple would have been nice too, but I like this color just fine. I really like almost all shades of purple, so there's no complaints.
With a boge carto on there, the ipro is about an inch longer than an ego with mega atty, in case anyone was wondering. My hand is about 7 - 7 1/2 inches long, and it's the length of my hand, from tip of the carto, to the bottom cap.
It fits nicely in my hand. It feels a bit large, but I'm sure I will be used to it in no time. It's really only a tiny bit fatter than the ego I was used to. (i'd guess somewhere around the diameter of a nickel?) It's also lighter than I expected. Roughly the weight of 2 egos. It does feel sturdy and well built though.
The voltage is set about halfway between the yellow and red (on this crappy boge carto) and I am getting a stronger TH and about the same as, or more vapor, than I did on the ego. 3 second draw on the ipro, as opposed the a 5-6 second draw on the ego. The vapor actually feels warm in my mouth, and combined with the TH, is much more satisfying.
This is *seriously* rockin those cruddy cartos. I would have thrown them away, they were so bad, but I kept them for emergency spares in case all of my attys died. I definately see me getting use out of them now though!
The flavor of my juice is also improved. My normal peppermint is very minty now. All in all, I'm very much in love. It is spectacular! Once my husband gets over his aversion to larger PVs, I can see him wanting either an ipro or a buzz. It would definately solve the issues he is having converting full time to vaping.
Also, I can see the problems that people have with picking their button. It's nice and soft, and begs to be picked at.
I am wondering about the plastic threads on the bottom cap though. It seems like they would get stripped over time, and it kindof worries me. Especially with my darling children who like to sneak into my stuff and twist things that are twistable.
Now a couple questions I have thought of. How long does it take to charge the batteries from totally dead? Should I be turning it off after every vape, or does having it on all the time not significantly affect battery life? Once out of warranty, will I be able to send it in for repairs if necessary?