I've had Geico for years, and I always wondered how they'd be if I ever had a claim (never had a claim over the last 30 years). Well, I hit a deer and then crashed with my ACR this summer, and they've been reasonable to deal with. I'm going through some valuation issues with them - my car was a really rare one, and they don't take that into consideration when coming up with values, and they also aren't being too fair about considering virtually brand-new modifications that were installed. Other than haggling over the value of the car, though, they've been responsive and communicative and I get the impression they're trying to be as fair as they're allowed to be.
Putting a street car on the track is always a risk - and crashes on the track are never covered by typical insurance policies. The best thing to do is to talk to the insurance agent when setting up the policy and see if you can get wording that states you will accept full responsibility for track-related events and you'll obtain separate insurance if your car ever sets foot on a track. There are insurance companies out there that will work with you on that and not cancel you (AAA was great to me when I had them years ago). Or, just get a track-only car and just get the track insurance for when it's being towed to the track and when it's on the track (homeowner's insurance will cover it if a tree falls on it at your house, etc.).