We have done two trans Pacific cruises & loved them both, hope to do more. If you enjoy sea days sitting on deck watching the waves, sitting reading a book or having a nap in a deck chair then you will enjoy it. Some times there are interesting guest speakers, it depends. Try it & decide for your self.
We didn't have an aft cabin but on our trip around the Horn the water was like a mirror not a ripple. It all depends on the weather & time of year, we went around in Jan.