There are many methods of hair removal so the question of whether a lady shaver is a good idea for you depends on how you like each method and which parts of your body you would like to work on.
Shaving is a popular and effective temporary method of hair removal. Although you need to repeat it every few days to remain smooth it is much less painful than waxing or using an epilator and much less time consuming (or smelly) than using a depilatory cream.
However shaving is not a good method of removing female facial hair should you should not consider lady shavers as being useful for face hair removal. The problem is that the stubbly regrowth is so obvious on your face. The regrowing hair will feel very rough and unpleasant and if your hair is dark you may get a dreaded 5 o’ clock shadow before the hair is long enough to be shaved again. And the same issue is there whether you use a manual or electric razor.
A lady shaver is a great solution as a quick fix to leg or underarm hair however and you will find it very convenient especially if you get one of the wet and dry razors you can use with water. They have an advantage over a manual razor in that you can use them without water too and you will not suffer little nicks or cuts that you sometimes get with a manual razor.
Are they worth the extra expense? It depends on your circumstances. They tend to last at least a few years so they are quite cost effective if you shave your legs regularly as compared to using a disposable razor in the bath. If you will not use a lady shaver regularly however it is probably better just to buy the odd pack of disposables at the drugstore when you need to.