I have had experiences with tens of Dell servers with the same model NIC having the same fault. The servers were absolutely under maintenance. I fought with tech support for weeks before I was finally told it was a driver/firmware issue and that I had to work around it (and lose performance for the sake of reliability).

Maybe if I had hundreds of servers Dell would have helped me out. At the scale of tens they told me to take what I got. The Customer got a lower performance solution and nobody anywhere could help them for any amount of money, short of replacing the gear.

That's just a performance issue. I've heard horror stories about reliability-- All the way down to disk firmware and RAID controllers. I consider myself lucky.