I changed scales half way through, which has made it a bit messy. My old set were v old and weighing at least 4lb too heavy (yes I know it sounds like a cliche, but they were!) so I invested in an all singing, all dancing model by tanita. I think the weighing is v accurate with these, and it also calculates things like % body fat, bone mass, muscle density etc. My one boggle is that despite reaching (and exceeding) my 'ideal weight', and despite being within the right bmi, and about the same as I weighed 10 years ago, these wretched things still label me as obese! Not just overweight, but obese!
I know they work on averages, and it's based on % fat ratio to muscle, which naturally dminishes with age, but it's still pretty irritating.
Still the weight bit is ok, and it has a useful memory function for the previous weeks weigh in, so no mistakes.