I am considering an Exmark hydro WB maybe next year. I see you make a 52" in the Turf Tracer and the Turf Tracer HP. and I am wondering what the differences in the two are? frame size? track width? engine options? electric clutch? overall weight? etc... I am not decided on a 52 or a 48 but I had these questions. Also, how are the belts kept tight on your machines ? Spring tensioners or manually adjusted tensioners?