Now in the bils case he has one block which slopes particularly at one end but the shack block is flat and neither present rocks or stumps so presumably the twin bar blades ( are twin blades common?) should be OK re a disc and retractable blades. Must measure the cut size but it sports an 18HP Briggs and Stratton with belt drives to cutters and transmission. Now belt drives can be quite robust and offer shock protection to shafts and bearings which can prevent bent shafts, broken shaft keys and the like in a potential shock situation like a mower.
Now recall from that sizing article he probably only needs a 30" cut but I noticed 2 new Husky mowers for sale both with 19.5HP motors and the pics look similar but one has 30" cut and the other a 38" cut. Ipso facto you'd expect the 30" model to be a better buy for intermittent block mows up the river when the grass might be up 300mm or so. Fine having bigger cut for the same power if you're cutting back regularly like home, but the 30" 19.5HP seems a better bet for his particular circumstances. Also does your mower have hydrostatic drive or belt drive re performance. I ask because the bil and others might need to compare some apples with apples here and not just brand names. Also, despite the brand some may have the wrong size mower for the job as clearly there are a few important criteria to consider here.
Most hydrostatic driver lawn tractors are belt driven hydrostatics. Your BILs case is not unusual.
Husky's model number usually tells you about their machine. LTH2142 means lawn tractor, 21hp 42 deck.
Up here the grass grows faily quickly and thickly so you need the HP. I reckon I mow my lawn approx 48 times per year. In the wet season it needs to be mowed every 5-6 days.
I reckon the 30" mowers are good for 1/2 acre blocks and a 42 for 1-2 acres and a 50-60" cut for 2-4 acres and a 72" cut for above that.
My next door neighbour has a 2009 or 2010 husky with 15hp and 38 " deck. He traded in his old Cox a few years ago and really regrets buying the Husky. His mower really struggles with the thick grass. He has the same size block as I do but it takes him nearly twice as long to mow his because he has to slow down his mowing speed. His lawn has never looked as nice as mine. Not enough horses.
In you BILs case I reckon 19.5 HP with the 30" cut might suit him. So long as he has plenty of HP (20 or more) than maybe up to a 42" cut.
My family members own blocks between 1.25-1.75 acres.
These are our machines:
Husky. 2006 17hp. Koehler 42" deck 2 blades hydro/drive
Husky. 2007 21hp. Briggs/S 42" deck 2 blades hydro/drive. (now have a Toro 30hp 50" dk zero turn)
Husky. 2010. 21hp. Koehler 42" deck 2 blades hydro/drive
Husky. 2011. 21hp. 42" fabricated deck 3 blades hydro/drive
I cut my lawn yesterday afternoon. Here is a pick of the front taken this morning(still covered in dew)
