As for the question about HST versus gear, the hope here is that Getut's machine is a 1 in a million. Although based on the other thead, I suspect there are various levels of HST problems and he has the extreme problem while others may have minor problems and some may have none that they notice. That said if you get a good one, you got a good machine.
Now then the issue is what is better for YOU, a gear or a HST machine? Generally put, HST is more productive (quicker & easier) when doing things like mowing and working a FEL. The Box Blade work would probably be more efficiently accomplished with a gear tractor. Based on what you wrote, you will likely spend more time doing tasks well suited to a HST machine than doing tasks well suited to a gear machine. Realistically either machine will do any task, all are compramises in terms of productivity. I prefer HST for the work I do, but I mow, blow snow, till the garden, and use a PHD & FEL and an HST works great for those tasks . . . occasionally I use a blade. My tasks are better suited to HST and that is why I prefer it. Use tasks as your guide on the type of transmission you choose.
I noticed in your profile that you have 40 acres but your post said mowing 4. I am going to presume you have 40 and 36 of that is NOT going to mowed. If you are working any of that 36, then your tractor choice, in my mind is questionable because it is a tiny tractor. Mind you I think it is a good machine, but a CK20 on 40 acres is at least a superficial mismatch. Now if you are really not working the 36 acres, then its a good fit.