To go on from the quote below and from a few other points, i think we all need to remember that harry is at the beginning of his life as a wizard, and in most cases other wizards consider him to be a child, however that being said, i beleive they also FEAR him - i disagree with the earlier comment that almost all of the white council could defeat him through skill rather than raw power, because as we read the books, harry grows and becomes more than what he was, he created little chicago, and that in itsell according to bob was a massive acheivement for any wizard, he is mostly self taught and he learns most of that in the thick of battle, he is self depricating also so when he talks about how "good" he is, i actually beleive he sells himself short.
he has the leansidhe as a body guard and the white council have had cause to end him more than once and they havent.
his birth apparently is meant to give him power over the outsiders, perhaps the only mortal man that does, so he is valuable.
personally i beleive we dont know nothing yet as to where his main powers lie, but he is a combat wizard through and through, however his skill at making items is rapidly improving.
(furthermore to that note about items he creates, notice that they get better because his old one failed, and he put more thought into the different types of incidents he would likely be subject to ergo, the only thing in his way, his the limits he puts upon his own psyche)
keep in mind that harry is a lonely man, he likes his lonliness like a companion, but that has to breed self consiousness from him
The problem about Harry's particular talent is that rarely he got somebody in the book other then himself who rated his skill. And if there is, it is rarely someone with enough credibility.
Harry said he is good with Thaumaturgy but that is just his own opinion and it can be argued that he just think himself good in those area because he is been doing that for years. No particular gifted talent there.
If we say he is good with creating enchanted items: armored coat, energy rings etc, Well, in Death mask, when Susan ask him why he do not carry enchanted items like the rope he use to tie Susan, he said he is not good enough. At the same time, we find out in White knight that Ramirez, who approximately the same age as Harry in Death mask, perhaps even younger, can make a shield glove with the principle of entropy which probably is as good as any of Harry shield bracelet before White knight.
When he animated the T-rex in dead beat, he told Ramirez that is just hard work, not complicated. Again we can argue that it is just Harry being modest, but no one other then Ramirez compliment it, and Ramirez is just a young wizard with limited amount of magical muscle. He do not have enough expirience to rate that feet and due to his own limited amount of strength, he might think that Harry's feet in animating the T-rex is impressive because it is beyond his own strength.
If we say that his massive strength is a skill by itself, well, nothing to be argue there. That is only a matter of oppinion.
Other then Bob's comment in Proven Guilty about Harry having a gift creating things like 'Little Chicago, we do not have anyone with significant level of magical expirience compliment Harry on a particular magical feet.