I've used insuremytrackday.com recently. The sign up process seemed simple enough. Not had to claim (thankfully) so cannot comment on how they would fare in that case. They were significantly cheaper than a very well respected and paying provider.
The insurance policy for Nurburgring Nordschleife will also include cover for damage to Armco at the circuit – which you are liable for - and can add up to a serious amount of money.
I have always used Moris, but touch wood never had to "use" them in a claim. Two friends have, and both I think were very happy with there service and speed.
