I have that Green Balaanza scale. I did test it (and periodically test it) buy using something for which I KNOW the weight (i.e. 2 lb box of sugar).

Its within 1 lb....so my "large" suitcase never goes over 46 lbs. I'd rather take a second suitcase and pay the 2nd suitcase fee. cheaper than overweight.

I had "overweight" issues in La Romana two years in a row. first time I fell for it. Next time I knew better and refused.

Leaving Cancun last year same issue........turns out they had not zeroed out the scale. I KNEW what my suitcase weighed, and I KNEW they were wrong (frequently).

I had no problems last year Sept 2008 leaving Aruba.