I prefer the more resilient versions for several reasons. Though I haven't been able to join as many Dailies this month as I was in May, June, and July, I had a lot of success then with lists that walked the line between Paradoxical control and Cantrip Gush-Delve.
The main reasons I've preferred the Paradox lists with a Mentor win-con that are not "Opal Soup" are:
Lower frequency of hideous mulligans.
Less games auto-lost due to inactive Mox Opal(s).
Better equipped to win despite Stony Silence/Null Rod.
Monastery Mentor is the best answer to Monastery Mentor
Able to change roles, particularly post sideboard. For instance, when an opponent can be expected to overboard v. Paradox with Null Rods and artifact hate, I board out Mana Vault, sometimes EE, and 1 or 2 Outcomes, morphing into more of a straight up Mentor deck.
Paradoxical Mirrors. The control/resilient versions have been substantially more favorable in matches v. the combo lists.
I think the main issue is that this dude might as well cost 10 to cast within the context of your shops deck, and to use a spot in the 75 on it is probably irresponsible. If it had a tax effect instead of a reducing effect I would be more inclined to give it a chance.
In the actual meta (see the last vintage challenge) it could make sense to maindeck Containment Priests. Dredge and Oath are stronger than ever and the Ambush Viper mode of the Priests make them even usefull in almost any matchup but Storm and Paradoxical.