Having considered both options recently, we were happy to proceed with the Polaris Insurance as this cover is underwritten by a well respected Company in the Indusrty, (i.e. Zurich) & is a very competitively priced contract. This policy would appear to provide very comprehensive cover, from the policy document, which is issued to you at completion.
If you have a CAM mortgage, I think you may be able to obtain a slightly discounted rate if you take out various insurances, cards or an Internet account (which is brilliant) with CAM, & so if you had a big mortgage you would need to crunch down the figures to work out whether it would be beneficial to take out CAM's policy, i.e. the more expensive contract. Maria at CAM in Sucina is brilliant at explaining the options to you if you want to explore further, & she speaks excellent English.