Definitely. I am not sure what metrics Solarflare beat others (presumably including Intel) on, besides software support (OpenOnload implements the BSD sockets API and doesn't require software changes, while DPDK and others implement their own). In my testing, the X520s have been capable of both sending and receiving at line-rate.

It's possible the Solarflare NICs could be better at some metric like latency, by a matter of microseconds (only speculating here), but I can't see how they'd consider that worth the extra money for HTTP servers.