Had the opportunity to play Quarriors using both rules variants including with Quarmageddon.
We've been using the Quarriors Card Picker website to randomly select the cards we use, because it will usually give a good mix of cards. For this game, we had what I can only describe as an amazing field of dice for use with the new rules, especially the double buy.
We had both a Mischevious Imp (Cost: 2) and a Scavenging Goblin (Cost: 3). The Imp's ability let its owner cull a die from their used pile when it's destroyed (and/or when it scores depending on its burst ability). We got the Goblin that added two dice to its owner's active pool when destroyed. Needless to say, both of these dice were very popular throughout the game. A lot of turns went like this: Roll dice, summon one or two Creatures, buy a Goblin and an Imp. I had a couple of turns where my active pool started with +4 dice because I had two Goblins get killed. And the new culling rule ensured that there were usually one or two Imp and Goblin dice available to be bought.
We also had the Corruption Spell that destroys all creatures in play (this was our sole Rise of the Demons card) as well as a Growth Spell (+2 Quiddity and draw and roll another die). The final Spell was the Life version that moves all of your Creatures that get destroyed into your active pool. This Spell saw a lot of use. We all had at least one Life die in our pools.
Rounding it out, we got a Quake Dragon and Lord of the Quarry, Warrior of the Quay and Troll Behemoth. The other Creatures I don't remember, because this game was owned by Dragons, Imps and Goblins.
With all of the ways to add dice to active pools, combined with Portals (which of course sold out pretty early) we had some crazy dice pools getting rolled. I had one turn where I rolled a total of twelve dice, summoning a Dragon, a Lord of the Quarry and an Imp (total summoning cost: 9). Insane.
The new culling rule creates some interesting, and tough decisions. Should you earn Glory for your Dragon (meaning you'd have to cull it) or hang onto it (we had the version that can't be attacking by level 2 or lower Creatures). If you score a Dragon and choose to earn Glory, you lose the Dragon, but if you choose not to earn Glory you can keep it around. With the high number of Imps and Goblins in play, Dragons were highly useful for both wiping out opponent Ready areas as well as safeguarding your own weenie Creatures so they can score for Glory.
If definitely adds a much-needed layer of strategy to the game, increases the play time to a more reasonable amount of time to allow for building and tweaking your dice pool, and keeps the pool of available dice interesting since scored Creatures who earn Glory get put back out for sale.
I will say however, that the usefulness of the new rules is really pretty dependent on the Quarry. You need to have two or three cheap Creatures and a lot of good Creature and Spell abilities available to maximize the new strategic options created by the variant rules.
I enjoyed the game with the new rules enough that I'll very likely always suggest using them in the future. They really make a game that I already liked a lot into a much deeper and strategic experience.