Interesting. The slight niggle is that in order to get the Boardman for £685 or so is that I have to use it more for journeys to and from work than not. This works out about 360 miles per year during winter months (15 miles per week, about 6 months of the year), and the summer would be riding my motorbike into work. Unless I forced myself to take the train more. And then there's the issue of leaving a £1k mountain bike at the station all day long, even in a sleepy village.
If I don't go down that route, I can get a 15% discount off bikes at Halfords, and might be able to pay for them with the vouchers I get a 10% discount with. My spend on them is unlimited, whereas I am restricted to a bike costing £1k on the cycle to work scheme.