I am about to approach my local Toro dealer about purchasing a new Toro 500 series mower with a 60" deck that has either a 28 HP Kohler or a 27HP Liquid Cooled Kawasaki engine. I know that the KAW will be more expensive, but how much difference is there in these engines? I know the liquid cooled engine will give me a longer engine life. Will it be worth the diffeence in price? NEED YOUR OPINIONS!!