You're looking at this the wrong way. The enigma is meant to fit differently than the bike you already have. Higher stack with same reach means that you will be more upright on the enigma vs the Jamis. You need to decide if that's what you're actually looking for. Also the 54 isn't going to be more flexy just because it's one size smaller. You downsize if you want a racier position and upsize if you want more stable feeling bike.