The Encore frames can handle much more powerful cartridges, but it has a heavier frame. The Contender makes a lighter, handier firearm if you're not interested in really high power cartridges.
I'm a big Contender fan, my brother loves his Encores. However, most of my Contenders are set up as pistols, his Encores are set up as rifles. Now if I needed a 30-06, 7mm Mag, etc. (which I don't need right now) I would be shopping for an Encore. Most of my hunting situations can be handled within 200 yards, so I choose to shoot 30-30, 375 Winchester, 7x30 Waters in my Contenders.