Yihi's take on Micro USB:
On their $200 TC M Class mod they offer a one year warranty. Except for the USB port, which has a 90 day warranty. Although the port charges, they highly recommend not using it to charge the battery because basically they have no confidence in the robustness of the port. And they are very direct and specific about that. My understanding is that prior models had a separate small USB port board, teathered to the main board by a small ribbon cable, making it relatively cheap to replace. The newer M Class has the USB port soldered directly to the main board, and in my reading I *think* the standard fix was to replace, not repair that main board, making it a very expensive failure, and keep in mind the 90 day warranty on that port. And given that it is a TC device, it makes firmware updating potentially very important. Perhaps unlike the Radius which will likely see few if any FW updates after the initial "market testing", just like the P3, which has not had many updates past the early and beta updates. So you could argue the port is not very critical.
There are two ways to look at Yihi's policy... one is that they have a crappy warranty (or crappy engineering) on a $200 high end product. The other is that they take a very practical approach and recognize that people want to use Micro USB because it is a standard and cables and etc are readily available, but at the same time it is not a very robust standard. And it isn't robust enough to reliably survive frequent charging. Take your pick.
It will be interesting to see how Provape handles the warranty on that port- will they warrant obvious water corrosion damage if it happens? Do they have some magical secret sauce that protects the tiny internal contacts from corrosion and other damage, yet passes electrical signals?
When I recently bought an iPhone 6 I bought an OtterBox case, specifically because it has a very water resistant hinged plug protecting the Lightning charge port. It is not guaranteed to be water tight but it was the best protection I knew of for that. Just to say this issue is very important to me. Right wrong or indifferent, but I have some experience with crappy Micro USB port failures.
There have been some comments here that all the USB port discussion is much to do about nothing. You are entitled to your opinion, but I strongly disagree. I think it is worth discussing because it is a "design compromise" to some degree or another. This will not likely be your father's Provari that could be dropped from a 5th story window into a bathtub and come out working most of the time. That's worth some discussion in my book, even if it disrupts the discussion about hamster wheels, hamster plugs and color selection.