We had a 2011 Keystone Bullet 250RKS for the last three summers and never had a warranty issue. Friends of ours just bought the same one you did. Keystone makes a good product.
I highly recommend Bal-X-chocks for the Bullet. Our biggest complaint was the bounce and wiggle in the floor, even with all four corner stabilizers down and tight. Our Dalmatian paces when he wants out (2am) or he's hungry (4am), and it drove us crazy. The X-chocks improved the situation a lot.
Enjoy! It's great that your older kids want to go with you. You'll have many happy family memories.
Elizabeth