well, maybe i am really wrong, but i cant see ilusionist been played too much.
I mean, when we think in it we always think in good bronzes like griffin or other tall bronzes (or even good bronzes with orders).
But lets try in a real play.
Since its a 4p card you whant to use it in round 1, and also you whant to have both in hand (i will ignore, for now, Mushy Truffel).
But in round 1, unless you have some damage its not easy to put a good bronze card in Gy (or you use insta kill cards, but you problably dont whant to use insta kill in bronzes).
So you will have 4 points (3+1) + and order and/or passive skill
problably 7 points (3+4) + and order and/or passive skill
total of 11 points and 2 orders for 2 plays and 8 provision - its not bad, but its also not good, special if you need both in hands.
In round 3 you will problably dont whant two 4 provision cards in hand, but if thats happens, you will problably play for more points than in round 1 but still not enought comparable with other golds cards.
Adding Mushy Truffel i think its a little diferente. First Mushy Truffel can trigger 2 times assimilate units. Also its plays alone for 9 points (3 from ilusionist + 6 from froth). But, for that, you still need to have damage units to kill your opponents bronzes in round 1, or play, at least, one 4 provision low tempo card in round 3