Spouse had a claim for lightly rear-ending another car at an intersection, when the front car stopped suddenly. Damage to both cars was repaired, and Ameriprise extended "accident forgiveness." Rates did not increase the following year.
I haven't had to use them for claims, but I'd expect nothing short of solid performance. This company is "the" company Costco refers their best members to. If Amerirpise was a flaky outfit, that relationship would be long gone. That says something for them.
As to rates, compared to other companies, you'll have to call them and ask for a quote, since everybody is different. With your current policy in hand, call in and ask Ameriprise for a quote for the same coverage. They'll give it to you over the phone. You can decide if it's a better rate. My guess is it will be.
Dave