I tune mine like a guitar aswell. It's ADGCEA (so it's up a fourth) but yes, the intervals are the same. I've been looking for about a year for a small instrument a bit like a guitar but with shorter neck and doubled strings and I was very interested in some 5-pair mandolaesque things I saw in Brighton but I didn't have any money. in Spain I saw these. The first one I asked about was 2800 euros but mine was 110. I am interested to learn the real instrument but for now while I'm travelling, it's my mini guitar that I can play tunes on too (when I've learnt them all in the new keys...)