The zero turn will probably mow your yard in about half the time you do it in now.  But if your wife is going to run it, I would suggest she try one first, a neighbor? or someone's.  They ride ruff.  She may or may not like it.

As a couple of guys have said, if the wife is running it she needs to try them out.  My wife and I have similar mowers but hers operates just a little different than mine.  I would suggest the brand is not nearly as important as getting a commercial duty mower from a good dealer.  We have had residential and commercial duty mowers, and had them from different dealers.  For our area the local Deere dealer is hard to beat for service and has a fair price. But just because it is green doesn't mean it's built commercial.  I can buy a residential duty Deere zero turn from Lowe's, but it is not the same as a commercial duty from a dealer.

We had a Husqvarna that mowed as good as anything and better than most.  But every woman who drove it came back commenting they needed ... ummm .. better support.  It rode rough.  And our local dealer just could not turn things around in the shop fast enough.  We had a fairly simple problem under warranty.  It took nearly 3 weeks to get it back.  We had a warranty problem with my new Deere Z930R (it was actually a problem that a tech bulletin was issued on. When I took it in the service guy said he had my name on his list to call this week about it)  I got it back in 2 business days.

Once you get a zero turn you won't go back. We now have 4 in the family, 2 Deere's, a Woods, and a Big Boy.   I did buy a used $100 lawn tractor to pull the lawn roller with last winter.