Purely by observation. I seem to catch more plague and poisons with the metabolic fortitude edge that I did prior to taking it. The added resistances don't show up in 'score damage' either, but that might be by design. Was wondering if anything it wrong with it or I've just had some bad luck.

Thanks.

The edge gives you an additional boost to saves, which it appears to be doing correctly. There's no possible way MF could negatively impact you.