I have not had any issues with Nashbar or Performance in 3 years of ordering. The only single issue that I had was an order that stated "in stock" and it was not. They did ship the remaining components of the order, and the out of stock item came a few weeks later. I normally pay the extra $'s of I need something ASAP, and if you time it right, you can apply a coupon and off set the additional shipping.
Something to consider - My LBS will match their prices! All you have to do is bring in the printed item, show that it is "in stock" and if my LBS has it then they match Nasbar or Performance no questions asked. I'm sure not all LBS's do that, but check w/your local LBS.