[thenomad]

I bought the Herman Millar Mirra - the version down from the Aeron - about 4 years ago.

Was it worth the cost? Yeah, yeah it was.

Ignoring the ergonomic benefits, it's just a damn good chair. It's very comfortable. The tilt options are particularly good. I've been known to drag it into the living room to watch TV on if I'm having a bad posture day.

And the lifetime guarantee is really nice, and appears to Really Mean Lifetime. The seat started going about three months ago - I phoned HM up, and a new seat turned up in a truck about a week later.

I can imagine not buying another chair for 10-15 years or more, and at that sort of timescale, it's a bargain.

(See also: the Captain Vimes "Boots" theory.)