Disciple is amazing and wins games single handedly
Perhaps on Xbox against random opponents it does, but at rank 30-40 on steam she has been by far my least reliable and hardest to protect finisher (asside from gearhulk but he comes with other perks).
If you do wait to play her (to still have mana open), actually protecting her from hate is generally more efficiently done via counterspella than her own ability; it's a lot of mana and exiled cards required to leak down an opponent with 8 or 9 lands. At least PWs do something instantly when they land and are vulnerable to far less in the way of direct removal. I'd much rather keep my opponents creature hate dead (virtual card advantage) and if I'm protecting my finishers from my hand anyway, her other abilities just aren't relevant that often in esper control.
Don't get me wrong, she's great and I love her in other decks, but I'm not feeling her here.
I can tell you that it's same on steam, the best control card and best wincon for blue (wondering why she hasnt seen much standard play, maybe because of the dragons). Anyway if you dont consider her much while building your deck she loses some value, i mean using lot of pws and maybe enchantment sac removals.
You only have to find the right spot to play her. I usually play her with 2 or 3 mana left when opponent is tapped out, or i use hulk to bait my opponent and make him use his mana.
Also consider what could be a threat for her before you play her. Red has lighning axe that is the cheapest removal for her, white has dec in stone really cheap, black has sac removals also as creatures. The best removal for her (that luckily see almost 0 play) is the black eldrazi that makes you sac her on cast. But once she is on the board and you untap you have probably won, using well your resources in graveyard.
Idk why you feel that it's different in esper rather than azorius or other combinations of colors, if you opponent is trying to use removals for her he will probably spend his whole turn doing nothing. Also there are occasions in which using a counter from hand is more relevant that countering with her ability. But imo she is better than any pw as wincon in draw go control, and even more this season with commit, cast out and never. But it depends how you build it. Haven't touched esper yet, but the first idea i want to try is to cut Ob and Jace having as wincon only Disciple, Sorin and 2 Pulls.