I was doing the same thing about a month ago. I was originally going with the Asus because a friend got it and it looked awesome. After spending a lot of time the only drawback I could see with it was Asus customer service. When I went to order it from newegg it was sold out due to a sale they were having. It made me a little bummed but took the advice from countless Potn users and said I just can't go wrong with the Dell. So I got the Dell from Costco online. They had a good deal going as well and I thought if I didn't like I could easily return it to the actual store. But I didn't need to return because I love it.
I too thought I was going to be missing the extra USB 3.0 and HDMI connections. But in reality once I plug in a monitor I don't ever change cables. And DVI is digital anyway. No loss there. They even give you the plug. Now I can use the HDMI port from the GPU to hook my TV up, that is on the other side of the office wall in the living room and watch movies. Win Win.
I don't think you could go wrong with either unless you must have HDMI and more USB 3.0 ports.
Good luck,