First, my personal experience is with the Rocky...so other comments are just based on reading the Amazon provided information.
You know that I think the Encore is not the greatest choice....so we won't go over that again.
The Precisio looks nice, and maybe others have experience with it and can give you a more useful review. All I can say is that since it is really not that much less expensive than the Rocky...well, you see where I'm going. If others think it is as good, or better, than the Rocky, save the money. Otherwise...
The Breville would be ruled out by two issues...first, I don't like automatic anything (OK, that's just my idiosyncrasy...so not important), and of MUCH more significance is that I strongly recommend a doserless grinder that dispenses directly into the PF...not into a bin. Whatever remains in the bin after dosing will be wasted, as you won't want to use grinds that have been sitting in a bin, and will be tossed. The Rule of 15s says ground coffee goes stale after 15 minutes (and Kurmenal feels it starts going stale after 3 seconds!).
So, unless there are some very high praise for the Precisio...I'm still with the Rocky.
Thanks for that. My only reason to consider the others instead of going straight out for Rocky is I'm wondering whether there will be that much of a difference for drip. I'm sure it's a different story with Espresso.
Random link while googling around: http://blog.seattlecoffeegear.com/2012/08/22/grinder-throwdown-virtuoso-vs-smartgrinder-vs-rocky-2/