It's quite curious really.
I had started off with the K26RT-N MIPS-R2-108 version defined in this post:
tomatousb DOT org SLASH forum SLASH t-603465 (sorry, apparently I'm low karma)
And while the update completed without issue, I was unable to connect to the 5Ghz band. Furthermore, every time I connected to it; it would cause the entire radio to bounce, ie. loss of network. Wired worked just fine… just no wireless. 2Ghz or 5Ghz.
Wiped it accordingly, 30x3, and updated with the R2-109 and while it's running much, much better; I still cannot connect to the 5Ghz side with my phone(s) nor my MBP. At least it's not stuck in a loop.
I'm not missing it much but would rather have it available.