I have had both the S&W 460 and the Encore in 460 Mag. The muzzle break is not needed in my opinion. I removed my muzzle breaks in my S&W's and installed end caps. On the Encore I had it without a muzzle break and with, did not really notice much difference in recoil. Well I sold the Encore and I stuck with the S&W 460 Mag. I have had a total of 6 of them and I am down to one now. I stayed with the one I liked the best.
I chose the S&W 460 over the Encore for the following reason's, more shots, looks, performance in accuracy at longer distances. My S&W was more accurate than the Encore. I don't shoot them light bullets in mine, I shot the 260 and 300 gr. hard cast bullets. On occasion I will shoot some Hornady XTP Mag bullets.
If you are going to go with lighter bullets, the S&W hand's down would be my choice, with the gain twist, it will improve you accuracy. That is what is was designed for. I like the heavy bullets in my 460 though.
Good luck in you choice and let us know what you get. Oh did I say, I liked the S&W better.