Really like the idea of computers built for Linux, but I configured a system on their site and it came out to $3000, whereas when I added the components up it seems like less than $2500.
So I'm not sure there is quite enough incentive for me to pay the extra $500.
If that extra $500 comes with solid support, down to calling a rep and having a replacement box show up the same or next day, then it's a no-brained for any kind of professional.
If I lose a couple of days to having to figure stuff out with a faulty machine, as opposed to solving the immediate issue of having a box that works right now, I will have lost significantly more than $500.
This is why I buy Apple hardware with Apple Care, by the way. Whenever I've run into an issue I walk into an Apple Store or call customer service and have the issue resolved right away. Sure the up front cost is higher, but the time and money saved on not having to care is priceless.
It has to be said though, that the hardware is only half the story. I also make heavy use of spideroak and iCloud for backup of pretty much everything, as well as init scripts to get a brand new machine configured in less than an hour.
If these guys can provide the same solid hardware + support + cloud story (by themselves or through partners) then I'd say the price tag is competitive.
So I'm not sure there is quite enough incentive for me to pay the extra $500.