We used them for a week on vacation at the beginning of the month. I don't know how cost effective they are, but they definitely take up less space than an equal number of disposables. That said, I ended up hand washing covers every day - I had 3 GroBaby covers and one Flip. Nearly every time he pooped it got on the cover. Realistically, plain disposables would have been easier, but I just hate them so much!
Re: Grovia Biosoakers