If 'Normally' you're running a saw for only an hour or less, a couple days a week, I would consider a battery saw to keep on the truck, and then go with the 455 for the 'all day' jobs. Just drain the fuel and run it dry when you're storing it, and it should start right up when you need it again, with fresh fuel mix. You might be a perfect candidate for canned pre-mix, which will keep (unopened) on the shelf. Just toss the left over fuel in your lawn mower or something to use it up when the job is done.