For me Finn has probably only bowled two, maybe three, spells of any quality. His figures flattered him big time at Brisbane, yet he is the leading wicket-taker in the series with 14, @ 33.14. His economy, however, is over 4 runs per over, and therein lies the problem. He has bowled far too many half trackers, not bouncers, just balls put there short in length with no real intent, Hussey has been the main benficiary, then again all English bowlers have ensured Hussey has proved his capabilities in dealing with the short ball. This guy can pull/hook!!!!
Also he consistently over pitches aswell, for a big guy a drive is a shot he wouldn't want the batsman playing with any ease, and anywhere near as frequently as they have been doing. If you look at the likes of Ambrose, Mcgrath, etc, bowlers of a similar stature, offering the batsman a comfortable drive off the front foot would not happen too frequently at all. It is unfair to compare Finn with those two as they were world class once they'd gained the experience Finn hopes to get, but I'm sure these type of bowlers are what Finn will strive to be like.
It's early days, he's only 21, and this Ashes will be a big learning curve for him, and will help his development as top pace bowler. However, I would prbably look at leaving him out for Melbourne and Sydney.