I am a regular buyer at Letsbuy.com and have not faced any such issue in delivery time and product quality so far.
I am a techie so regularly buy various technological things like portable hard disk , Pen drives , wireless keyboard and mouse etc. And generally I get them delivered within the mentioned time and good quality at fairly discounted prices which I found to be the major benefit of the website.
I would want them to include more technological stuff in their range so that the site can become one stop shop for techies ;-)