That Problem Solver EBB looks like a great option. I almost went that route ended up going with the eccentric hub though I'm now second guessing my reasoning and I'm not completely sure I've got the right information. Hoping those more familiar with EBB's can chime in.
From what I understand, to convert your vertical drop out geared Mooto X RSL to a SS:
With the Problem Solver you'd have to pull out the pressed in bearings with their cups and throw in the EBB unit right? With the Problem Solver unit you'd then throw on your external bearing cranks. Sounds straightforward. To go back to the geared setup I've been told that you'd need to get a new set of cups for the bearings. Are these hard to come by? Cost?
With the eccentric hub I needed to build up a new rear wheel and just swap in my desired chainring on my crank (in this a Homebrew Components ring on my SRAM XX).
I ended up spending some decent coin on my setup with the primary rationale being the ability to swap between SS and geared quickly. If the cost of the swap is essentially a set of cups it sounds like the EBB may have been a better option from my end. No complaints with my eccentric hub.
Look forward to hearing any thoughts on making the swap with an EBB in the PF30 shell.