I am giving this app a 5 star review partly because I think it has the best balance of features and usability of all the text editors (many) that I have tried, and partly to counteract the fixation here on the price of the upgrade. $15 is not a high upgrade price for a $50 app, and you only have to look at the release notes to see that a lot of work goes into keeping Chocolat polished and compatible. (Why not think of it as generous that the dev allows you to use 3 for free on Mavericks?).
It is true that there are a lot of free and cheaper text editors that do the job, but Chocolat seems to me to hit the sweet spot: it has all the features I need (splits, flexible folding, extensive support for languages and themes with full customisability), all contained in an interface that is beautifully designed and congenial for the occasional coder. (And that icon makes me salivate every time I see it.)