It really depends on what your preferences are. Encore is "usually" generally more quiet than Wynn, but IME both Tower Suite rooms are fairly quiet. Encore rooms are a little bigger than Wynn. For the Wynn Tower Suites room, it's literally the same room as the regular king rooms, maybe a slightly different layout. So if you were expecting a suite, you'll be disappointed. Encore rooms are more of a suite since the sleeping and living area are kind of separated, while Wynn King and TS rooms are just a big open room.

The pros of TS King is that you get a private elevator for tower suites. For the breakfast, you get to have it at Tableu, which is excellent. For Encore TS breakfast option, you have to do room service. Also, if you're staying at Wynn, you can only use the Wynn pool (TS rooms does have it's own pool), but if you're staying at Encore, you can use both Wynn and Encore pools. You also get 4 complimentary items ironed if you're in a TS room.

For me, if I was going solo then probably not worth it. But if going with significant other or another friend, then yes. The Tableu breakfast is about $30-$35 per person so that upgrade fee is easily covered. Also, if you're staying at a TS room, you can use your room key to cut the line at Wynn Buffet, which can easily save you 1-2 hours if you were planning to eat there. A line pass would usually cost $15-$20 depending on the day.

Hope this helps. You can't go wrong with either option as both the Wynn and Encore are top notch properties in LV.