Glass weight watchers are biggest pile of poo ive ever had, mine didnt come with feet extensions so they didnt work on carpet... this is thing you need to watch out for!!
Ive got digital ww, plastic with came with feet have done me well, wer only about £15 tbh its all you need, shouldnt see scales as telling you how you should feel, you should be able to feel it within yourself & your clothes, scales can put your off or down at times.