tl;dw:

Balance is bad. Artifact Eithne is too strong and uninterruptible. The counters to it don't do enough against all in artifact decks without gimping other matchups.

The mulligan system means that players who start with a bad hand are doubly penalized as they not only have a bad hand but spending mulligans to try to make it workable is essentially losing carryover.

Hates the reveal mechanic. Highlights design shortcoming with homecoming in his opinion. Very high RNG as seen in cards with Daerlan and Spotters. Adds that the RNG in homecoming is too large, both with reduced consistency/mulligan system and 2x bronzes as well as some of the card design.

Xavier Lemmens is a badly designed card.

In conclusion, he's not enjoying gwent right now.