I personally like Discover more. It gives you more control over it and thus adds more strategy. Sometimes with randomness you end up with a pretty useless card. With Discover you can at least pick what seems to be at least decent. I mean it’s nothing like Zephrys where you get always the perfect card.
I once made a deck around Hench-Clan Burgler because it did seem to always provide a really good card for the situation almost like Zephrys. But playing with it I can say that it really isn’t anything like Zephrys. It’s just very good but not overly powerful.
Anyways, because of the additional element of strategy involved I would rather see more Discover cards. Of course over all classes. And they kind of do that. With Galakrond’s Awakening we got for example Boom Squad for Warrior and Twisted Knowledge for Warlock. Very nice additions for keeping the game fresh if you’re interested in that kind of playstyle.
If only there would be a mode where you could play with your own rules like no randomness and Discover anymore…