Quinn played on the left of a 3 man midfield for Hull, which I always thought would be his best position. He did well for them, they rated him highly and he was an important player in that team that won promotion. I think playing under Blackwell did him a bit of a disservice, he's always been a good footballer.
He's a fair bit older now though and has had injuries. Assuming he's in good condition he'd be a decent signing, he could cover for Fleck, Duffy and give us a left midfield option for 4-4-2. He's a hardworking player with a good attitude and would be a reliable squad player for anyone in this division.
Signing him (or anyone) on loan would be positive in that it would leave the door open for Whiteman, who will be first team starting 11 standard in the near future IMO. He'll compete for Coutts' place along with Lundstram.
I'd prefer someone younger and more athletic than Quinn though.