I had a full-size 9mm. Loved it! Accurate, smooth shooting, and very soft recoil. I got rid of it because...well, it doesn't matter why. I am working on getting the RO compact. IIRC, the mainspring housing is metal. Enjoy it!
Bought mine when they first came out. Had a local gunsmith do some trigger work. Couldn't be happier with it. It's accurate, easy to shoot and never had a malfunction. I have several 1911's including SIG, STI and DW, the only one I think is better than Springfield Range Officer is my STI Target Master.
I have the Range Officer Compact 9mm - the MSH is metal and I expect the full size is metal, too. However I did replace it with the two piece Nighthawk MSH/magwell. I love the Nighthawk upgrade and it let me get rid of Springfield's mainspring safety lock.
I have a 9mm RO and have absolutely loved it. I've had one failure and it was due to underpowered ammo not cycling the slide.
Mine is a tack driver and has an amazing trigger. I don't consider it any better or worse than the STI Trojan I owned. I have hit shots with this pistol that I thought were ludicrous to even try and if I were a better shooter I'm sure it would hit every time.
My only complaints have nothing to do with function. I wish it had a checkered front strap. I wish it had a cerakote or similar finish. I wish it had a fiber optic front sight. I wish it had a mag well.
These are all easy enough to do aftermarket and that is what I have done.
I recommend them without reservation. Take advantage of the constant springfield mag rebates!