Paranoia is my middle name! Lol. I recently bought 18 quid glass digital ones from John Lewis, based on their fab reviews, and they are wonderful. Was a shock cos they were 6lb more than my old ones, but these matched the WW ones so I guess my old ones were just rubbish and they gave me a different weight every time I got on them, these ones are consistent (after the initial step to turn them on).
And yes, I even weighed a cup of tea to see how much difference it'd make on the scales! One nice paranoid weigh-in I had tho was finding something in the cupboard that weighed 3lbs - what I lost last week - and it turned out to be a huge and heavy bag of flour!