[tines]

That post, while awesome (as is the rest of aphyr's stuff), is a lot to wade through to get to the point you're trying to convey. Can you spell it out for me?

[ackfoobar]

That typeclass resolution can encode some heavy computation, the example being n-queens in the article.

[tines]

That's only the case when you turn on the "enable arbitrary computation in typeclasses" flag, so I'd say it's not much of a worry.