Hmmm, wonder if its fixed the for me achillies heel, sd card corruption.
As I had multiple sd cards go bad, none of which were removed during operation (in fact, they weren't even disturbed, because they were wall mounted), I dug into it, and it was apparently a issue caused by the way the soc handled sd/usb connectivity being a bit of a fudge. As micro sd is a subset of sd, I'm left wondering if this fixes any of it.
And before the usual apologists say weak psu, bad sd card and all the other blah blah reasons trotted out on the pi forums, we ran four pi's in a test bed on a common rail regulated lab psu. 1 of them behaved impeccably, the other 3 randomly corrupted their sd cards with a week or so of stability testing. We bought the whole "its fake sd cards" like trotted out and tried various brands of sd cards, slow speed low capacity ones from the dawn of time, genuine oem's from reliable suppliers etc. In fact at one point we dual booted one with its base partition on sd and everything else on usb drive, and that one managed to corrupt both the sd card partition AND the usb stick.
The one good one could cope indefinitely with sd cards which had previously corrupted in the other 3 without a glitch. The only differential we can come up with in environment is we bought the first one early on in the b's release to evaluate, then ordered the other 3 much later to build out with. I note they changed assembly details between the two purchases.
The various patches which played with timings and slowed down the io helped a bit, but it never cured the problem enough to be able to rely on them to just keep working, which when you take a sbc and leave it somewhere to do its job for a year uninterrupted is a supremely important quality.
The worst about it was the continued denial, the fud spread on forums as it all being user error etc.
For us, too late, we've abandoned it as a platform now in favour of a more stable compettitor although I did wonder if the model c would fix it as it goes to a true flash chip, which is what broadcom designed the soc to work with in the first place.
Posting anon, because Ive got enough egg on my face recommending them in the first place without publically identifying myself as the culprit. Great toys though.