I'm not mad that it's 10GBASE-T, but I'd personally rather 10G over SFP+. The sorts of shops that can afford these probably already have some pretty burly networking infrastructure, and 10GBASE-T is both expensive and (IME) less reliable.
The encoding/decoding capacity of Ethernet-over-twisted-pair seems to be reaching a point of sharply diminishing returns and the hardware for 10GBASE-T is really expensive for what's been, in my experience, a less reliable experience than SFP+. I'd rather tell somebody who needs 10GBASE-T to use an RJ-45 adapter than to have to go grab yet another Mellanox card to stick in a computer this expensive.
But isn't SFP+ not compatible with 1G (i.e. can only be used with a 10G network equipment)? If you are selling a machine that people will plug into either a 1gbe or 10gbe network, you'd rather have some interface that can downgrade.
You can use SFP in an SFP+ socket, but not the other way around. The downgrade to 1GB would work fine.
Since this is still a desk focused machine vs. datacenter, I'd expect most offices to be wired to cat6 ethernet which can do 10GB if needed vs. SFP+ cables or SFP+ to Fiber.
The encoding/decoding capacity of Ethernet-over-twisted-pair seems to be reaching a point of sharply diminishing returns and the hardware for 10GBASE-T is really expensive for what's been, in my experience, a less reliable experience than SFP+. I'd rather tell somebody who needs 10GBASE-T to use an RJ-45 adapter than to have to go grab yet another Mellanox card to stick in a computer this expensive.