I shot a Vectrix and Drenalin before purchasing the Allegiance. Never shot the Gaurdian, too ugly for me. I chose the Allegiance because for me it had thedraw cycle, looks and feel I liked best. Very smooth draw cycle in my opinion. The Drenalin was also very smooth. I personally thought the Vectrix was rougher than both of those bows. However, that's just my opinion. As for my shoulders, they're just fine.