Quite different. Not quite like Swedish and Norwegian. It sounds silly to Finns, because it is similar but the tone is different. Many words especially in text are recognizable, although not the same, and you can decipher some stuff from writing. Still, you generally can't really follow speech. Now, many Estonians in tourism at least used to know Finnish or understand it but I don't know if this has become less common, although I suspect that's the case.
Hungarian is the other bigger language in the group (the Ugrian part of the Finno-Ugrian languages), and it is not intelligible to Finns. There are vague similarities though, similar to how the Germanic languages all have certain words that are different but have similar roots. Numbers are like this between Finnish and Hungarian it seems.
Nej, tyvärr.