There is another important thing to note here. "Вот тебе и +subject" is strictly third-party. By that I mean that the subject cannot actually be that subject. E.g.

Вот тебе и учёный

I can say that to another person who's not the scientist, but I can't really say that to the scientist face to face, because that wouldn't make any sense. I think that's because of тебе and no, you can't just exclude it from the phrase, it will change its meaning in that case. Anyway, face to face I'd most likely switch to тоже мне учёный to convey pretty much the same thing. I guess this is where the 2 can be interchangable.