There are a couple for sale on Gunbroker. Hope we can get some reviews in the next few weeks.
Robinson XCR-L 300blk conversion 9.3" : Other Gun Accessories & Parts at GunBroker.com
"Necessity is the plea for every infringement of human liberty. It is the argument of tyrants; the creed of slaves."-William Pitt the Younger
If anyone on the forum is interested let me know. Forum prices are a little cheaper.
Barrel lengths are the same(9.3"). It's the location of the gas block that differs. The micro conversion uses the original micro system specs. The 300 standard is slightly longer than micro setup.
The Robarms website says they are going to make a 7.? that will come out flush with the front of the "mini". They say it should be gtg with supers but will need a supressor to work with subs.