Great piece of kit
I bought the Osprey Mk IV plate carrier G1 Used from Cadet Direct about three years ago, when I was a cadet. I bought it with a cummerbund and some pouches. Having used it many times in the field, and having since used it for films and airsoft, I can say it is a great bit of kit.
It's great quality and very comfortable.
Maneuverability is slightly affected when wearing this vest, as it is a combat-Grade vest, not some operator plate carrier. However, it's very hard wearing and the fact it is MOLLE compatible is great. I recommend only buying official Osprey pouches if you want authenticity, but also Condor do great pouches that are indistinguishably similar in terms of MTP pattern.