Got mine a couple of days ago, took some sorting of new CentOS partition and setting up for process to change it to IR mode
Got that done last night.
Performance goes up to 1500/800MB/s, from about 450/275MB/s for each SSD in IT and no better with them RAID'd via OS
Only issue with my R720, with HP H200 (with BIOS as booting from) and a H710p, the system won't boot past checking for devices
In IT F80 mode system booted fine
Had to in the system BIOS disable port that F80 is in from BIOS loading, then worked fine
I'll play about some more to see if I can narrow down where the issue is
Not had a chance to check if I can boot from it, as plan is to install Server 2k19 on it
Anyway very nice to fiddle about with it, $70 well spent as I learnt a whole heap about Linux