iv got all my bikes insured with Bennetts. They offered my a multibike policy to insure them all on 1 policy but it only worked out about £45 cheaper and its a pain updating it if you sell a bike with a multibike policy so Iv just got separate policy's for each, (got lotsa meerkats ) Personally Iv got no complaints and never had anything but good experiences with them. Relatively good prices and the call center staff seem well informed and keen to help, only niggle is you can't change things online and have to ring them.
Bike-sure however wouldn't get my money if they was the only bike insurer on the planet after my last experience with them (I changed a bike on the policy and dispite them sending me a new updated insurance certificate with the new bike details on it they didn't update it with the underwriter so technically I was riding uninsured for 6 months, I only found out when I tried retaxing it and it showed up as uninsured).