As I will be riding predominantly on flats and very light hills in an urban area, is it worth buying BBSHD over BBS02B? Would that extra £200 make any difference whatsoever? I don't think all that extra power of BBSHD would ever be needed, and from what I read BBS02B seems to be as reliable as BBSHD? Are there any real benefits of coughing up the extra if the bike will (almost) never see hills of more than 10% ?