i have one, it helps till you get used to what certain sizes look like.
it also helps to track food so you're more conscience of what you're eating, even if you don't do it all the time.
i recommend a digital one though. and i normally set it to grams, it's just more precise.
also it's a handy measuring tool even if you aren't keeping track.
need a cup of milk for something, put the bowl on the scale and measure 240g, you now have a cup of milk (or most other liquids) and don't have a dirty measuring cup.
easy to remember because 1ml of water weighs 1g, so check the nutrition label and see that 1 cup is 240ml. weight of milk is close enough to water, some
heavier lighter liquids (like oil) could be different.
same for dry stuff like oatmeal. on the nutrition label - 1/2cup is 40g, so if you need 3/4 cup just weigh out 60g.
the nutrition label is your friend here, most of the time it has a dry measurement and then the associated weight in grams.
as was pointed out to me, the oil would be lighter, not heavier, i was in a rush when i did this.