Obviously we have to give him a chance and call it at the end of the season, but it would make for a poor forum not to give opinion prior to that.
I don't think he is technically a better player than Clarkson, he's a little bit more athletic. This should have been the season we challenged Clarkson to up his yardage in games and become more of an all rounder, which he's shown plenty of signs that he's capable and willing. That needed game time, which Thelin is no longer willing to give. If we can't turn a player like Clarkson into at least a £1.5M player, then I have my doubts we're going to get more out of Aouchiche. Realistically, we'd need to be getting £3M return to make the wages outlay worth it. I just don't think that there is a £3M player (Lewis Ferguson, basically) there. He's not got the physical attributes to make it an obvious buy for, say, an Italian club. He'd be the type of punt Lecce took on Ramadani, which would land us <£2M, covering the cost of purchase and additional wages probably.
The only reasons I could see is taking up the offer is if we've suddenly decided to up our spending more generally, or we've already had agreement to buy for £2M from another club, and we're basically using our leverage in the agreed fee.
None of this is criticism of the player himself, just the high cost of his signing. Our player trading model shouldn't really be being used for this type of signing. It defies logic a bit.