Used to have my Beetle with Footman James, no complaints about price or the way that they handled me.

As for the excess... depends upon your car and what you're happy to fix from your own pocket I guess, and you know your circumstances.
Basically such an excess means that for repair work less than @£500 your cheapest option is to fix it using your own cash (basically the repair has to be worth more than the £400 + the expected premium hike as a result of having made a claim).
If your current insurance has a lower excess and you're happy with them then is the £40.00 premium saving enough motivation to move? For just £40.00 you might find that Auto Torque can match the quote? You may find that the broker would rather either find you a more competitive quote or take the hit from their margin / commission than lose your custom.
If money is tight then I would recommend going to Martin Lewis's MoneySavingExpert website and finding the right deal through the forums there and then buying your insurance using a cashback site like Quidco.
Lucy (SWMBO) sorts all of our insurance and last year on her Clio found a policy for £140.00 fully comp' and then bought it through Quidco and got £100.00 cashback... making her fully comp' insurance £40.00 for the year

Obviously everyone has a unique set of circumstances, so I'm hesitant to be "you know what you wanna do, mate" about it... but please do check out the links and have a look, Martin Lewis is a straight-up guy and you've probably seen him on TV giving debt advice and the such? He doesn't endorse anything shady, but looks for loopholes that benefit the consumer, keeping more of our money in OUR pockets

Hope this helps (not a HPE owner... but isn't a Dedra just a HPE with a boot

)
ian