edit 2: Not sure why he linked to the EVGA board. I don't think it's considered "better" than the MSI. Maybe it's his personal experience with them?
http://www.anandtech.com/mb/showdoc.aspx?i=3671&p=11
"We are going to keep this simple. Hold our feet to the fire and we’ll tell you that of all the boards we tested, the most consistent performer was the
$230 EVGA P55 FTW SLI E657 (using a Tyco AMP Socket). At its price point, there’s nothing available on the P55 platform that truly beats it for raw overclocking capabilities."
OP, it sounds like for your purposes a UD3R or even UD2 is more than enough. Both have 2 eSATA ports and UD2 even has a firewire port. If you are not going to be overclocking, or using CF/SLI, there is no advantage to MSI GD80 whatsoever. Also the fact that you can't flash BIOS in windows as easily on MSI's as you can with Gigabytes and Asus is a big disadvantage for novice users. Gigabyte and EVGA boards also have dual BIOS chips. If your bios flash gets corrupted on MSI, you are toast.
When it comes to features Gigabyte GA-P55A-UD4P walks all over that MSI board since it comes with SATA 3 and USB 3.0 ports. Yes these are not native off the P55 chipset, but they should be significantly better than SATA 2 and USB 3.0 once drivers mature. I dont' see any reason for the $210 GD80. These top boards are meant for overclocking.
If you are going to spend $200 on a mobo, might as well go with socket 1366 and get 6 DIMM slots and Gulftown support (if that matters). Socket 1156 is a budget socket. Once you start spending $200 on a mobo, you have to seriously consider 1366 imo.