When did you sign up for this?
As I've seen guidance that the final payment is something like 25% of the total cost of the bike. I could be wrong though
No, at the end of the scheme after wear and tear the bike is valued at 25% of its purchase price. The way the scheme works is that the employer gives the bike away to the employee. This is counted not as a gift but as a payment in kind, which is taxable at the regular rate of 20% or whatever of the value of the bike. 20% of the 25% means in effect you pay 5% of the original value of the bike as a final payment [plus possibly national insurance, can't remember but that would bring the payment up to more like 7%]. Not all schemes work this way though, some simply allow you to buy the bike off them at a fixed price. I think the city council ones use the latter, expect to pay nearer 10%
I work for Birmingham City Council who've just introduced the same scheme, same suppliers, and its barely worth it. They don't refund the VAT so the C2W calculator is meaningless The overall saving for a regular rate tax payer is 18% in the end, which is achievable without the scheme by just shopping around. The interest free payments isn't that good since most of my LBSs offer that anyway.
I've bought a bike through the scheme just because I was going to buy a 2012 model bike anyway and it's convenient, but if I had been in the market for an older model I wouldn't have used the scheme since much better deals are going at the moment on remaining 2011 stock at the big online retailers.
If you are also a BCC employee be warned, the administrators are fecking useless, supposed to be 3 - 4 weeks turnaround but they're taking > 2 months at the moment.
And if you are in Birmingham and are interested in a 2012 bike I recommend Red Kite Cycles in Shirley, they were the best LBS I could find on the scheme's approved supplier list. Spesh and Trek mainly, though not exclusively.
And to answer the OPs other questions, cross bikes make great commuters. Versatile and bulletproof. Don't know the wheels one the Boardman one, mine's a Specialized Tricross, but I have 25mm slicks for summer, the 30mm ones that came with it when the weather gets a bit dicey, and 35mm Marathon Winters on at the minute.
shoot that's a long post, only came in to find a camera recommendation.