I highly recommend Impetus. Impetus basing is genius, with each unit based on a single large base. You can also do single figs in a large base so that you can play Hail Caesar and Impetus. I do like being able to port my armies across multiple sets of rules.
Most importantly, Impetus is fun and the rules are not too long or difficult. I did a review of my first game of Impetus on my blog
here. I also painted 3 Impetus armies in 15mm which you can see
here.If I could find a partner in Minneapolis, I'd be painting and playing Ancients in Impetus.