This is a review of the Series 1 as well as the 2B. The "stars" are hard to read in my browser, but I selecte 5.
Concerned about the 2B price, I initially bought the Series 1, and used it daily for 1-1/2 years That alone should indicate how satisfied I was with the Series 1. There was a (pleasurable) learning curve. At some point I figured out I could trim the standard surface electrodes to various sizes and shapes, which was a major breakthrough. I'm also getting a lot of mileage with the combination of a surface electrode and an elastic strap. Battery life with the Series 1 was exceptional and I got months of daily use from a single battery.
Seriously concerned about having a backup should something terrible happen to my Seiries 1 (but I want to emphasize that I have had NO problems with either unit) and leave a sudden emptiness in my life, I ordered a 2B. The greatly expanded adjustability makes it several times more pleasurable than my Series 1. I wouldn't say my time with the Series 1 was wasted, and would definitely recommend to anyone with the same initial concerns I had, but the 2B is the real thing :-) The audio CD is something else, and putting the CD on my iPhone really simplifies use. Setup with 2 channels is pretty cluttered (then add the audio cable...), but single channel use is still very gratifying, and is how I generally am using the 2B. (I guess I grew up using one hand, while the other held the pictures ;-) I'm definitely looking forward to trying the Triphase cable as a way control "clutter", though.
I strongly recommend getting spare cables. The quality is excellent, but they do wear out, and you don't want to be caught short. I've also gotten a lot mileage by renewing my surface pads with the Tac Gel. Battery life with the 2B seems significantly less than with the Series 1, but then my time spent with the Series 1 has gone up ;-)
If I were designing the 2C, I'd add some memory and explore loading the CD and other programs directly into the unit. I'd also try to figure out a way to add a 2nd adjustment control. Finally, IOs or Android versions of the Commander software (which I haven't tried) would be awesome. (Has anyone tried making tracks with something like GarageBand?)
Customer service is great, and overseas delivery times have have dramatically improved with the switch to DHL.
I'll draw a final analogy by comparing my E-Stim units with past girlfriends, all of whom I love dearly. (The girlfriends, of course). My girlfriends didn't necessarily give perfect handjobs, and required some respectful training, but was it ever fun.