i have about 12 lawns that i mow weekly on the side of my full time job. i currently use a 2002 JD sabre with a 17hp/42in deck home owner machine. i would like to up grade to get things done a little faster. last week i demo'd a hustler fastack ztr and i got things done in a lot less time. it seems like a good ztr for 12 lawns but i am also considering a 48" gravely walk behind(but i have never tryed a walk behind. none of my propertys have small gates to worry about. is it a pain to make 180 turns with a gear driven walk behind? will the walk behind get me done as fast? 2 of the lawns are pretty big and take me about 2 1/2 hrs to do. is there anything else i should consider?