Nev's Left Boot
Corbisiero is a very good player, i think he provides a good balance of tight and loose play. I've rated him for quite some time.
Joe is better in the loose imho, and i actually think he is a decent scrummager and will get better. THe best thing he offers is a very clear long bind.
I'd agree with that assessment. The long bind is something that will benefit Joe in the longer term as referees come to expect it. If Wayne Barnes's analysis at the (excellent) Meet the Ref session a couple of weeks ago is in anyway indicative, refs are looking for the TH without the put in to bind properly and stay up - the main thing they'll ping a loosehead for is binding on the arm. Once refs get that Joe always binds long, the onus will be on opposing THs to keep the scrum up.
That said, I'm sure I've heard one ref this season (I think it might have been Pearson) penalising Joe for binding on the arm - one of the more inexplicable decisions I've heard.