[citation][nom]megawinner[/nom]Are you seriously going to load up your machine with 4+ hard drives? Probably somewhere around 99.9% of users won't want more than 2 hard drives anyway, so just use the 6GB/s SATA ports and there's no problem at all. This could be annoying for super-power-users or servers, but then again, only the 3GB/s SATA ports are affected, and this kind of user would probably want to run 6GB/s anyway. It's such a non-issue.[/citation]
The bandwidth of 6Gbps is not really needed for most people, but plenty of people have devices that need SATA connections. How many SATA III ports do these boards even have? You'll want at least one for main drive, one for a storage drive, one for an optical drive. Some will want to connect a front eSata port with an additional port.
Personally, I have 8 SATA ports, all of which are populated, though I realize that is way more than normal.