I have 2 acres as well. Take me just under two hours to cut as i have lots of stuff to deal with...trees, beds, patio, pond etc.
What I considered was that with a ZT I will be down to about one hour per cut. I do about 20 "cuts" per year between cutting grass and mulching leaves. So I will put about 20 hours a year on the machine. Then I looked at the warranties. 300 hours for the Ariens Ikon and 500 for the Apex. I expect that, if not abused, we can expect 50% more "life"...giving 450 hours for the Ikon and 750 for the Apex...likely more. Both have Kawasaki engines, therefore the longer warranty must be due to the transmissions and spindles. but spindles are not expensive and easy to replace. Not sure if there are other components that are better on the Apex.
Dealing with my 2 acres, I have a useful life of 22 years with the Ikon and 37 years for the Apex. I am 70. Doubt I will make it to 107...LOL
There is a $1800 difference in cost. After 22 years, at 6%, that grows to $6500. If I am still cutting grass at 92, I will have a $6500 party..
If I had more acreage, or lived where I need to cut more often, the Apex could be justified. In my situation, the Ikon seems to fit well enough.