I did a quick internet search to see what the "experts" say.
http://www.consumersearch.com/bathro...rtant-features
Consumer reports also liked digital better. So does Good Housekeeping. You might check out ratings on epinions.com once you have one you are interested in. We have a digital Tanita that has kept constant for years.
Consistency is key - any two scales could weigh you differently, you just need to know how you are changing over time. There is an old saying that if you have two clocks you will never know what time it is. I think the same holds true for scales!