I switched from a Kinesis Freestyle2 to a Matias Ergo Pro, and I'm pretty happy with it! It feels much more solid. The springs feel a lot like the old Kinesis Evolution (which is to say, "like springs, not bubble wrap"), and it's a lot quieter.

I ordered it almost a year ago, and it only just arrived.

There aren't a lot of options for two piece, separated keyboards.

Things I like about the Matias:

• The connecting cable is removable. The Kinesis was hardwired, and wasn't as long as I liked. The cable that comes with the Matias is also kind of short, but it's just a standard 3.5mm 4-conductor cable, so that's a cheap fix.

  Update: No, that cable doesn't work reliably. The failure mode is that sometimes modifier keys get stuck on until you power-cycle the keyboard. This cable fails in the same way. I need a TRRS cable that is around 25" long to replace the 18" retractable one that came with, but I haven't found one that works yet.

• The bottom row is much taller, and Ctrl is wider.
• Esc is tall and awesome and in the right place, so I don't keep hitting `~ by mistake.
• The Delete Forward key is banished off to the Fn row, which is great because now I can stop hitting it by accident all the time.
• Right-Shift doesn't have ↑ to the right of it begging to be hit by mistake.
• The bank of function keys on the left is smaller, which is nice because I never used those anyway.
• Fn is a chord instead of FnLock, so you have to hold it down to switch between function keys and media keys. I'm on the fence about this but I think I like it.

Do Not Want:

• Separated keyboards are supposed to have 6^ on both sides! The Matias has it only on the right. This is horrible. It is literally ruining my life.
• Opt is only on the left side, instead of on both sides. Cmd is on both, but really I want all three on both sides.
• There's a NumLock key to the left on the N that turns the right side into a numeric keypad. I hit it by mistake all the time and then v50 c6. 64 352 5 6 53. 5' 250 6 .050.
• Guess what keycode the Paste key sends? If you guessed Paste you'd be wrong. It sends Cmd-V and Emacs sheds a single tear.
• For some reason USB Overdrive doesn't recognize it as a keyboard at all, so I can't remap any of its keys.

Still, it's an improvement overall.