Regarding the RB2572, I haven't yet moved more than 6" of snow with it. It is rated as too big for our machines, but I wanted the 17" high moldboard as opposed to the 14" moldboard on the 1572 because of snow removal duties. I also like the extra weight back there.
The majority of my use for it will be snow removal, so I figured that the extra beef would be fine as long as I wasn't doing too much dirt work. I have however, put more dirtworking time on the blade than snow clearing time, and haven't yet had an issue with the 3030 being able to handle it for dirt work.
One thing to keep in mind is that you will have to set the 3pt hitch up a little higher so that the blade frame is parallel to the ground to minimize or avoid constant adjustments when angling the blade to either side. Because of the extra 3" of blade height, the frame sits up higher than the 1572, so the lower links need to be higher up when the blade is on the ground. It also impacts ground clearance when raised, but I've got it set now at about 9" of clearance when raised, and with the frame parallel to the ground so that I can swing the blade angle to either side. To do that, I put the top link in the bottom hole which is supposed to be for the Landpride Quick Hitch setup.
The 2572 is much beefier than the 1572, and should be a little better suited to welding more steel so that I can add a hydraulic angling piston at some point. I don't necessarily think that the 1572 would be all that bad, but I don't like when you're moving snow and it falls over the top of the blade so you have to go back and make another pass to get the drive/road completely clean.
I've seen your link to your relocated joystick, but the location I have mine at now seems to be comfortable enough that I don't have plans to move it again. I think if I were to move it a little closer in, it would end up in my way more often than not.