A lot of great responses here already. I wanted to offer a few thoughts.

What does quality mean to you when it comes to concentrates? For me, I search for solventless rosins that try to capture the flavor and essence of the strain/plant being used.

Concentrate quality is typically determined by:

1. Input material - What did they use to make the concentrate? Cured nugs, trim, whole plants? As they say, “Fire in = fire out”
2. Extraction method - Do they use some type of solvent (e.g. butane) to create the concentrate? Or is it solventless, and maybe created via ice water hash or press methods.

Comparing outputs:

• Distillate: While typically the most potent and used in vape carts, I’d generally say anything with distillate will be the least representative of the original material used (no taste), and something I try to avoid. Distillate = headaches, for me.
• Live / Cured Resin: Resin is extracted with solvents, and retains more of the plant’s profile of terpenes and flavonoids. A great budget concentrate option. This is typically where you'll find shatters, waxes, budders/badders, crumble, sugar, etc.
• Live / Cured Rosin: Then we have Live Rosin which is extracted in a solventless method, and to me, is the best concentrate available. Full of flavor and character that is representative of the original plant/strain used. I've seen rosin come in shatter (fresh press), sauce, and badder-y variants.

EDIT: Also if texture can be an issue, I know people who swear by the Hot Knife by Puffco: https://www.puffco.com/products/the-puffco-hot-knife