Originally Posted by DA Quality Lawn & YS
A 20.5 hp engine on a 48" deck reg mowing will not lack power - I run that same combo now.
There's several of guys on here (especially in the HO forum) who own a 910 and many of them would disagree with you, and have done so already in other threads. With the size of the pumps and the weight of the machine itself, it's getting close on power on flat ground in thick wet grass, but it should be OK.
Like I said above, but add in any hills at all, and it's gonna be underpowered a bit. You can't accuratelycompare what your Toro will do to what the 910 will do unless everything is identical weight, deck design, blades, pumps etc.