Depends what you consider the tourist spots. Amstel is nearer to the Rijksmuseum and Van Gogh. Kimpton is better for Dam Square / Anne Frank House / red light area!

I had a terrible stay at the Kimpton (until they gave me the Penthouse Suite as compensation) and some rooms are very noisy as they directly overlook the road junction. On the other hand some Amstel rooms are currently covered in plastic sheeting!

The two hotels are polar opposites of each other. Also worth noting that the breakfast at Amstel is probably the classiest you will ever eat and, on that basis, worth it for a splurge. The cost also comes down sharply if you pay for the Club Life Experience at the Amstel. Impressive pool as well. In many ways, if you are NOT planning to leave the hotel much then the Amstel is your best bet, but I assume this does not apply to you.

There is a bakery about 45 seconds walk from the Amstel and a brasserie opposite - not sure if it does breakfast though.