Some points of critique:
1. I don't like the separation of [unupgraded] vs [any player] in PVP.
* People with upgrades lose a lot of the advantage that upgrades give in the first place.
* The separation creates a developmental gap where people with just a handful of upgrades have no proper bracket to play in, as [unupgraded] renders their upgrades useless and [any player] is far more likely to pit you against an opponent with significantly/fully upgraded deck, against which someone with 3-4 upgrades is not going to have any statistically significant bigger chance of winning from as someone with 0 upgrades.
* People with deck strategies that require upgrades (such as those that use Animate Weapon while the deck provides no air quanta), cannot pit their deck against similar developmental level, because the separation done here renders the whole deck useless as cards can become unplayable when they get changed to regular cards.
* It decreases the pool of people to pick from when assigning random opponent in each mode, which brings me to the following point....
2. The matchmaker is seemingly too simplistic.
Tonight it pitted me against the same player 4 times in a row. While this isn't the end of the world, it is both annoying and boring when the deck match-up is one where a specific outcome is almost guaranteed. (e.g. opponent has a deck that just so happens to be the one your deck has no defense against).
Perhaps a possible fix is to have it wait just a little bit longer so it gets more people to pick from? I don't mind waiting like 5-10 seconds extra if it means more variation in opponents chosen for me.