Wetsuit decisions

Looking for some advice. I am female, about 5'2" and 138ish pounds, broad shoulders/chest.
I rented the 2XU SC:2 Sleeveless Wetsuit from wetsuitrental.com. They sent me a Women's large and it's a little bit loose in the legs. The upper body fits comfortably (maybe too comfortably?). It was very easy to get on and off (possibly since it's sleeveless). I haven't swam in it yet.. will try it this weekend.. race isn't til mid July.

Should I drop down to a medium?

Also, if the 2XU wetsuit would cost me $180 to purchase slightly used, would I be getting better value for my money by buying the Xterra Vector Pro X2 since it's almost the same price? (assuming they fit equally well) Is the Vector Pro X2 worth the extra $50 over the Vortex 3? I am a beginner, but plan to use whatever I buy for several years. Any advice??