I'm not a fan of those very restrictive rule sets. While most are fine by themselves when the RNG combines 3 of them (or even just 2) it can lead to very uninteresting games. Sometimes, all it takes is one of them and a very low mana cap plus just 1 or 2 splinters available to have an uninteresting game.

While it is true the super restrictive games reward wider collections and give some use to otherwise very bad cards, which in turn, gives an incentive to own more cards, I believe the cons outweigh the pros. The cons are games where both players choose the same or very similar teams, and that there's often no room for skill and it comes down to what cards you own/rent. The pros are selling more cards but since most players are on a budget, only whales benefit from this as they get basically all the cards.