That's purely something you'll have to decide.
IMHO, a lease only makes sense if you know UP FRONT that you will walk away from the asset at the end of the lease. If you've got any idea that you might want to keep the asset, modify it, etc. a lease probably is not the right way to go.
I'd be careful about the deal in other respects as well. The dealership is almost certainly not the leasing company. They'll have to pay off the leasing company to get your truck. Make darned sure that you don't end up owing anything. For that matter, they've approached you. There's money on the table for you here.