54 vs 60 inch deck time savings

[JeffinNE]

Looking at replacing 20 year old LT190 with a 48 inch deck with a 54 or 60 inch ZT. Looking at slightly used JD Z920M or Z930M.
Currently takes right at 2 hours and 20 minutes to mow 3 acres (some parts smooth, some rough) with trees, berms, garden for obstacles.
Have looked at some of the mowing time calculators and based on my current time I must be mowing around 3mph. Guessing I could go 5-6mph on the ZT.

Newly calculated mowing times with 54 inch deck are about an hour less with a 60 inch deck saving another 7-10 minutes. Based on this minimal savings the 60 inch deck doesn't seem worth it??

Would have a hard time looking at another brand as family has been JD people back to my grandfather but hear the Ferris suspension decks are incredibly smooth. Neighbor let me try his Z960R with 72 inch deck a couple years ago and wasn't much of an improvement on the rough areas (maybe just need to fill these areas with compost/topsoil or till up and start over...the drought the last few years killed off quite a bit of the fescue lawn).

Thoughts?

 

[oldnslo]

Any concerns about clearance between obstacles with larger deck or fitting through door in storage area? Neighbor bought a bigger deck that had problems with both of the above.

If ground is rough I doubt you will drive much faster on zero turn vs what you have.

Does Deere have independent suspension on front wheels or are they rigid?

 

[JeffinNE]

Any concerns about clearance between obstacles with larger deck or fitting through door in storage area? Neighbor bought a bigger deck that had problems with both of the above.

If ground is rough I doubt you will drive much faster on zero turn vs what you have.

Does Deere have independent suspension on front wheels or are they rigid?

No clearance concerns but a good thought.
It was pretty rough when test drove neighbors so maybe just end up going from 3 mph to 4 mph plus turning efficiencies of the ZT.
Pretty sure Deere fronts are rigid.

 

[arto98607]

I have mowers with 60" and 72" decks and based on my experience, in the long run one should have a 72" Diesel powered mower if mowing 3 acres
regularly.
That is if looking 10 - 20 years ahead...