I don't think I can help you too much but seeing as I just went through researching and eventually buying a new lawn mower, I'll through in my 2 cents.
I wanted a ZTR also - due to landscaping, trees, and general stuff on my 2 acres. The residential equipment at the box stores is entry level stuff and similar in quality (integrated pump and wheel motor rather than separate motors and pumps). I'd decided on either JD or CC initially. I noticed a few returns with seriously slashed tags but full warranty at HD. I thought I'd probably go that route hoping to get a deal and started going to check them out every day to see what came back. I asked the manager which brands come back most often for warranty or return - Toro, CC, then JD least. I did the same at Lowes - Troybilt, Husqvarna, then JD least.
I ended up getting none of those. I bought a JD X324 with 4-wheel steer. The uncut radius is 9" - its not ZTR but close enough for me. Cost a bit more than the entry level machines but it also has a 4-yr warranty.