I used to shoot short bows and will admit they are mighty handy in the thick places I tend to hunt. However, I have come full-circle back to longer bows (currently my shortest is 62" and longest is 66"). For whatever reason, I shoot the longer bows better. More stable? Yeah, probably. Smoother? Most of the time. I'll let the physicist argue over the mechanics of it, I just know what works.
With that said, I still love the idea of a short bow. I did have a Wing Thunderbird (52-incher) that was a shooter but I let it get away. I have had others and may one day try more but for now I'm fairly content that longer is better for me. I've also found that with a little extra effort I can use the longer bow in the places I used to think was impossible.
All things being equal, shoot the shorter bow if you can do so well but don't be afraid to go longer if it will improve your accuracy, consistency and, most of all, confidence.