I went with the illusionist primarily for the +2/4 for acquiring spells/allies.
Evading a monster to the bottom didn't appear to be terribly useful since Ezren's combat spells tend to be strong enough to crisp anything that comes along since defeating a bane is almost always better than evading it even to the bottom.
Augury/Scrying for monsters or barriers was the most common first thing done to put those far away or on top for the villians/henchmen/useful barriers.
In our 5 man party, with haste and the auto-explore after magic I didn't find myself needing to use allies for their discard powers especially after adding swipe to the deck. Swipe with Ezren reads: Take the really great boon that you can't use and explore again. It really isn't uncommon for Ezren to nearly clear a boon heavy location in a single turn.
The items for Ezren really started getting better after the role card was chosen. Every deck slot of mine went to items after maxing out on spells, which surprised me due to how relatively poor they had seemed prior to deck 4.