I thought the joy-cons were ok as a controller and I have very big hands, I liked them so much I decided to skipping the pro altogether, that´s until I found a Pro Controller on Sale (got it 50%)...
The battery lasts forever (40 hours or so) I had to recharge it last monday since buying it, so I took the joy-cons out (I hate playing with wired controllers) and put them on the grip, now I do find them very small, it´s like I´ve been spoiled by the pro-controller; I just couldn´t go back.
Now I use my joy-cons only for certain games or on the go; for everything else I use the pro. The only cons are that the triggers aren´t pressure sensitive and that the buttons are just a tad too large for my taste; still worth every penny, get it if you find it on sale