Site layout is fantastic, models are pretty and can carry off the clothing well, easy navigation.
I find the items I've ordered from ASOS to not only be expensive but seem to be made of inferior quality material. The worst of all is that in my experience the colours are not true to pictures at all. I ordered so many dresses and tops and my cream tops looked YELLOWISH in reality, like how they would when you put a white clothing in the wardrobe and it gets stained yellow with age, and my faint yellow dress turned out deep yellow, and my babypink top looks like muddy pink. I am not exaggerating. Very disappointed for my first purchase with asos. Extremely not value for money in my personal opinion.
If you want to buy from asos, I would advise to go for black items. I find their pictures to be seriously unreliable. It is very important for clothings from a website to look true to their pictures, but asos's pictures are definitely far from looking like how they look like in reality. Due to the lighting I presume, but that is not a valid reason and the website should improve on this. Forever21 can offer items that look like how they are on the site, I believe asos can too.