What categories do you guys use to determine what makes a good deck?

If it's fun, it's good. If it's not fun, it's bad.

How fast it generates Æmber, how well it denies Æmber, how well it deals with large boards, how well it builds boards, in that order of priority.

Where the synergies are between your cards and if they are spread between houses. Each house has there own thing they are great at, but did you get that in your cards?

Does the deck have anything that lets you "cheat" the rules? Key Charge/Chota Hazri, Helper Bot/Phase Shift, Relentless Assault, etc. These are the kinds of cards that let you make more than one key, play cards from different houses on the same turn, attack with more than one house.

Do you need to use your creatures to reap? Some decks have 10 aember symbols on cards they play, some have 30. If you have Shadows, you may just be able to let your opponent do the reaping for you and you use your creatures and actions to steal it, which is actually a two aember swing since they lose one and you gain one.

Are there any combos? This could be anything from a simple Virtuous Works + Nepenthe Seed to having three copies of Glimmer and Mimicry/Nature's Call/Persistence Hunting. The first one has an easy setup to just gain 6 aember from two cards and the second one lets you sit in one house over multiple turns while being able to control the board by playing your opponent's best action card, returning their two best creatures (preferably from different houses) and your Glimmer, or just locking down their board through exhausting for multiple turns.

There are assuredly some decks that are going to be better than others, but being able to find these things in each deck will bring them closer to parity. The difference is going to come in the people piloting the decks. There is no card that just flat out says "you win", but there are ways for each deck to be played optimally. You just need to find out which of your houses work together, how many cards are going to be good in each situation, what role your deck plays, and when you need to mulligan and/or discard cards from your hand to churn through your deck. In most games I play, I typically have to shuffle my discard back into my deck two or more times. The more cards you see each game, the more your chances are of getting to play your cards that actually matter.

What is the deck trying to do and how well does it do it? Does it have cards that work against that? How many games did I have to play with it to figure any of that out? Did I have fun playing with it?

Pretty much my criteria at this point. Once I think I have a handle on the deck I label it consistent or inconsistent and leave it at that.

Any of several criteria:

1) Does it have a gimmick that I think might be fun to play?

2) Obvious synergy between cards in the same house?

3) Synergy between cards of different houses?