He wasn't bought for the u-21s, but to start there and make it into the first team squad by the end of the year (see below for Hughton's comments). He's the wild card and unknown. If he's good, and scores/creates some goals for us as the season progresses, then the window's rating goes up from...
It's been fantastic, but just how fantastic isn't entirely clear at the moment. How good Harper is will prove to be the key, in my view. So a tentative 8, although that could shift in due course, hoping that Harper tips it up to a 9, or even beyond.