Ignore the advertising claims. They're all slimy.
To pick an insurer, you really have to look at how they handle claims. Some are the scum of the earth and the rest are just scum. If you have an accident or issue, you want one that is simply scum. Otherwise, they'll just take your money and screw you when you need their help the most.
I *hate* insurance companies. It's more or less legalized theft considering the mandatory insurance laws. Not everyone is insured, of course, but I can't get into that without getting into various politics. Which means those of us above board have to purchase even more insurance to cover those without.
As for dealing with insurance companies... well, I try to find common ground and solutions that work in all of my dealings. I'm generally forgiving of opposing counsel and give them courtesy extensions, the benefit of the doubt, and so on. That usually pays off down the line and is worth it.
But with insurance companies, I get to be the giant a-hole lawyer. I start out with the biggest threats, won't budge an inch on anything and never hesitate to open up on them.
The sad thing is you have to.
Otherwise, they'll screw you. You practically have to threaten them - and sometimes instigate - scorched earth litigation simply to get them to follow what they agreed to do in the contract you've entered with them and paid a lot of money for. The calculus is that it is more profitable to deny everything until litigation costs threaten to overwhelm that savings. [/rant]
Motorcycle insurance is all over the board here, too. If you are riding a financed sport bike and are under 25, watch out. My '85 Nighthawk 650 isn't bad at all, but that's on a multivehicle policy, I'm 37, and have a clean record.