Personally I can't stand the guy and I hope Brook gets that fight with him to prove he's the far better boxer......But what did people expect against Vargas? His first serious fight in over 2 years, with the KD aside, he's comfortably gone 12 rounds and if a bit sharper, with less ring rust, he probably would've finished it earlier. Khan's chin is never going to improve.....Even though I largely think the major problem is his defence. The shots which sent him down and wobbled him were both flush, due to a leaky defence. That isn't even taking into account the preperation that Vargas had, who's been very open about his lack of training for past fights.
Khan really struggled to make 147. Khan had to strip down to make welterweight at the weigh-in but yet still wants to campaign at welterweight and demand Brook fights him at welterweight. Khan is barely still able to make welterweight, he's kind of stuck between divisions at this point. But it's petty and stupid for him to demand Brook fight him at 147. Khan's last two fights were above 147. As far as his performance, I thought it was OK, but at the end of round 10 Khan did a little dance from a nice right hand right on the chin from Vargas. Personally this version of Khan would struggle against Pacquiao or any of the titler holders at 147, and possibly would get KTFO. However I think at 154 he'd do a lot better. But he seems to really want that Pacquiao fight, even more than a Brook fight.
Khan is what he is. At 140 with roach he was big enough to, against certain fighters, overwhelm them and get them out of there. But he's always struggled with durable come forward guys, he's never consistently put in good performances. His career PEAKED against maidana who I think bought into his own hype that he would ko khan with the first jab he landed, obviously getting a bruised spleen in the first round didn't help him. But ANY fighter who can survive the first few rounds (which at 147 is most of them tbh) is always in with a chance against khan. Amir just isn't that good, he's overall a B/B- level fighter who is capable of winning titles against opponents he matches up well with, and also of losing to lower level fighters who he don't match up well with.