Ends was pretty much an auto-include regardless of other factors for a while after it initially came out but its definitely less so now. The biggest factor against it is the same downside that nearly all forts and sites have, which is that you can't put them in play until your turn and even then many require you to wait until a certain future point in time to get the benefits. In Ends case this is when you attack so fortunately if you draw it on your turn prior to your attack you effectively get value immediately. However, if you draw it later on your turn or on the opponent's turn, its a dead card until your next attack. That may seem like a small amount of time but with how few turns top level games can take to end these days, a card being dead for any amount of time is a huge downside. Whether or not I play Ends now comes down to how much alternate methods of soul generation I have and what card type I would cut to fit Ends in. I'm much more likely to add Ends into a deck when I can cut a GE for it rather than an EE, for example, since the dead draw period of most GEs and Ends overlap heavily (drawn during the opponent's turn). However, even then, GEs are live draws mid-battle while Ends is not which is a huge deal. Thus if my strategy involves lots of cards that allow me to draw during offensive battles I'm less likely to cut a GE for Ends even if I had room to cut a GE at all.
That said, the card is still powerful in most decks and unless your goal is perfect optimization for speed intensive games, Ends is a high value card.
