We almost certainly let him go due to attitude, all the managers he played under had issues with him, which I didn't know at the time but I always thought he looked lazy when he was here. He might have been ok at Forest behind the scenes, who knows, most of it is assumption, but one swallow doesn't make a summer. His attitude after being promoted was also a bit distasteful, digging back at Warnock and then deleting everything boro related when we were the only ones who gave him a chance, very odd, but speaks volumes.
What we do know is Forest didn't really try to sign him (Wilder said they never even put a bid in), when signing known quantities is usually a big thing, especially for teams going up, and they spent an extra £6m on probably a lesser proven right back.
Cooper was bigging up Spence when he had him, but any manager would do that in the press, especially if they know what might happen if he didn't or started saying things as they were.
The way I see it, he's been at 6 different clubs in three seasons and had half of one of those out injured. He looked fairly promising for us, but we loaned him out to a rival, did ok at Forest (over hyped imo), but they never signed him when they easily could have, 4 clubs since then where he's done nothing.
I'd say I wish him the best, but I'll save that for the loads of other talented lads out there who would have snapped up the chance, with a better attitude. I think there's less room in football now, for those who aren't taking things seriously.
Like I said at the time, taking the £12m or whatever it was was the best business I've ever seen us do. I didn't believe for one second we would see the additional amounts. Spurs thought they were having us over by having ~40% of the fee (£8m) performance related, but we were having them over when the initial payment they paid (£12m) was worth more than the player was