I would say that overall the Omega has the most potential if you are an accuracy guy. Out of the box, I have seen very accurate Omegas and Encores. The problem is, there is variability and if your Encore isn't perfect there is not a lot you can do to it because of the break-open design (how many break-action high power rifles do you see in accuracy competitions??). With the Omega, you can easily float the barrel, bed the action, etc etc...the only weakness is the trigger can't be adjusted easily.
I would love to see the Pro Hunter breech plug incorporated into a version of the Omega. That design is industry-leading, IMHO.
Assuming both guns are similarly accurate from the get-go, Omega vs Encore comes down to personal preference, and I think both are at the top of the heap.
Two Bears, if you had to pound bullets down the barrel you needed to switch sabots not guns. I can't shoot 250gr SSTs with the supplied sabots in my X7 but it shoots everything else I've put down it with little ramrod pressure.