I wouldn't bother with a food grinder TBH. Having said that I did I have a Chicco Baby Papa steamer / mixer when DD was weaning and I used it every day - I thought it was fab. However with DS we are BLW and I have given my Chicco Baby Pappa thingie away to a friend... Mashing with a fork seems to work for us now (but he is a poor neglected second child...) .
I have one and use it quite a lot. It(IME) does not make purees very smooth, but no lumps as such just a bit thick IYSWIM. I have twins and find that everytime I give them BLW style food, one or both of them chokes and pukes and I am getting so fed up with it I am sticking to the mush for now with the odd bit of cooked broccoli thrown in.