They arent always going to be effective, but in the right circumstances, they can add a certain element of surprise to your deck
Its at its worst when there are lots of fast race matchups, like combo decks, burn decks, and very linear aggressive decks that arent usually removing your permanents (Goblins and Merfolk)
All new Leaders will get added upon availability
The snow-covered basics are an extreme example, but in general, Secret Lairs haven't offered a meaningful discount over buying the cheapest possible version of a cardthe upside is you get the unique new art
Tier 2 Toploadered chase cards (raw, not yet graded): High-value raw cards (e.g., a freshly pulled Crystal Charizard or Gold Star before grading) live inside dedicated toploader binders, not in flexible 9-pocket sleeves