Originally Posted by
well biked
You guys that are advocating a medium cage derailleur (with a triple) seem to be saying the OP should purposefully run his chain a bit short for the shift to large cog/large chainring to keep from having chain slack in the small ring/smaller cogs. Correct? No? Or are you saying he should size the chain long enough for large/large and make sure and avoid small ring/smaller cogs so that excessive chain slack isn't a problem?
OP- since you already have the medium, this is what you should do^^^^.