I think that Khan has good speed, he does have good technique, but only in going forward, he can't fight off the back foot, has little defence and definately has a suspect chin. If Khan fights to a particular tactic and the guy in front hasn't got much power, then he can deliver a result, but so often Khan doesn't stick to a game plan, gets into needless exchanges and either comes undone, ie Prescott, Garcia, looks in trouble or survives through luck, ie Maidana. Khan has heart, that is for sure, but his ring intelligence is pretty poor and as people have noted already, the first knock down punch he shipped came about because of the punches and stance he found himself in at that moment.
If we go back to when Khan first started, he was a fighter who liked to come forward and it seemed his goal was to try and blast everyone out of the ring within the shortest amount of time possible. Khan felt he could do this because the guys he was fighting were distinctly average domest fighters, who had been hand picked so they had no noted power and were often from a weight below, ie, super featherweight as was the case with St Clair. After a few fights Khan got over confident, thought he carried huge power and started to get in full blown exchanges and found himself on teh canvas numerous times. Not in a Garcia or Prescott fashion, but enough to suggest that the chin was a problem, that he didn't carry the power that he initially thought and that some major changes in style had to occur as he progressed through the levels.
Then came the Prescott fight which confirmed this view, up popped Freddie Roach and the career was re-aligned and some good victories followed plus a world title, media headlines, chat show appearances etc etc. By the time of the Judah fight, it was as if people had forgotten his earlier career misshaps, the Prescott fight, the maidana melt down and assumed that this kid was now all invincible, a Freddie Roach protege, akin to being the next Pacquaio, a fighter that was on the verge of fighting Mayweather. The fact was that Roach had concentrated on Khan's positives, his speed, his accuracy, his punch delivery, but had just tried to negate the weaknesses by covering up the chin, enforcing that in - out style, keep on your feet etc, but he never could alter Khans attacking mindset, toughen that chin or give him proper ring craft or a durable defence.
I think that Khan is a good fighter, but he has too many weaknesses in his all round game to be considered a truely world class fighter, that can take on comparable opposition. He looks good against has beens, ie Judah, Malignaggi and the never were's such as Kotelnik, but when he faces prime opposition, he looks fragile at times and its a roller coaster ride to the end of the fight. I think that Khan has gotten great PR since his career started and people like Jeff Powell write about him without critical analysis, full of praise, forever bulling him up to be not only a great fighter, but a champion of the people, a spokesman for a generation. It's total crap and whilst he is a good fighter, who could go on to gain other world titles, he isn't in the company of Mayweather, Pacquaio and other elite fighters. I think that people view Khan as being better than he is through a powerful media clique that willfully look past his weaknesses and seek to promote overblown PR, because at the end of the day, his marketability makes a lot of money for a lot of people