I really don't understand why we get all these posts from people whose clientele/region don't allow for 21"/30" use. It is in no way helpful to the OP. We do very small "garden" lawns. Have a Exmark 36" hydro, Exmark 30", and Honda 21". By far most used is the 30", then the 21", and finally the 36". I have seen Jim Lewis post on here several times that on small, tight lawns a 32" hydro offers him no noticeable time benefit over his 21". I think his voice offers enough authority that if it doesn't make sense to you, it probably doesn't apply to the lawns you are cutting.
I would never weigh in on someone asking opinions on a 52" vs. 60" telling them that they are wasting money on a ztr when they could have a 30"- it's obvious that we service two COMPLETELY different types of properties. There is a strong market for these 21"/30" for us guys in urban neighborhoods. Please respect that we have spent the time to understand what best suites our needs, and allow US(owners of these mowers) to weigh in on strengths/weaknesses. We are who the OP is addressing.