Santi BZ420 women's fit

[Pink_AquaRanger]

I'm looking to buy a women's santi bz420 and am looking for advice on how the suit fits. No store around me has them to try on and using the santi's sizing guide I am all over the board, i.e. arms are extra large but waist is small. I currently own a fourth element halo ar in women's medium and their sizing chart is the same issue, but I was able to try that suit on and fit in the medium perfectly. Online shops seem to be shipping for overseas or have a bit hefty of a return policy.

So I'm basically wondering if the fit of the two suits are similar or how true to size the bz420 is. Or how other people are fitting into the santi bz420s