I just bought a 2005 Aprilia Tuono and rang for a quote from my current insurer (lets call them Swindle) it was incredible, over £900! They suggested i go to their web site and get a better quote, a whole £127 was offered. So then I tried MCN compare. Best quote, from Devitt, was over £460 cheaper.
As it turned out both brokers were offering insurance underwritten by Equity Red Star. This means I got a quote using exactly the same details, for exactly the same bike, underwritten by exactly the same Insurer for £460+ less when i went to MCN compare.
Moral... Shop around, save a bundle or enough for a European return ferry journey, with your bike and a decent cabin