Great feedback - thank you!
To answer some of the previous inquiries, the diameter of the initial unit is a bit thick at 1.25", so it won't fit across the board in all carboys. We're doing a slimming design to address that issue where it should fit inside just about every vessel.
We're also doing a giveaway of a couple of our first models to a lucky few - if you are interested, we have a short, multiple-choice survey that auto-enters you into the "sweepstakes": http://t.co/VVLX07UZ
It's been listed on @thebeerbug's Twitter feed (also some new pics there of the device inside an active fermentation), but of course not everyone uses or enjoys using Twitter for updates...
You all have truly provided some great info above and beyond what the survey results will show. Pricing vs. features is always a major consideration...there are some interesting things we may be able to do here re: temperature control and re: cost based in large part on the info you have kindly shared.