Antigua: typically the brightest, and if it’s not one of the highest-altitude grown Antiguas, brace yourself for its harsh acidity in lighter roasts.The good Antiguas are best right at the 2nd cracks and can offer you a balanced citrus acidity (often tangerine/orange undertones).Some Antiguas do have cocoa notes in the darker roasts, but some are just flat.
Atitlan: a good Atitlan is your best bet for a chocolate-tasting Guatemala About 15 seconds into the 2nd cracks is where you find the acidity toned down, hints of earthiness to complement the cocoa flavor which complements the start of bitterness in the coffee taste. It sounds odd, but it’s a balance that works well.
Huehuetenango: my personal favorite because even a less-than-spectacular Huehuetenango is going to have some nice character and will be pretty easy to sell. The average Huehuetenango is best just before the 2nd cracks, and will feature traditional taste with fun undertones of citrus and a pleasant acidity. But a really nice Huehuetenango needs 5 to 15 seconds into the 2nd cracks which will burn off the acidity and citrus notes, but produce chocolate notes in the coffee. Try to find beans that are from Acetenango, a mico-region within Huehuetenango.