Passable — in either sense of the word.
Could be much better; while the price is consistent with other blogging apps (or lower), I have been using MarsEdit for several years with no massively noticeable improvements on updates. I think there could be far better value for the money (I really began writing this review as I was searching the App Store for more options)—it is okay for the basics and gives a good HTML editor, but I still often find I have to go to WordPress to make simple tweaks that MarsEdit can’t handle, like borders on HTML images.
If you’re expecting a replacement/equivalent for Windows Live Writer, MarsEdit isn’t quite as clean and straightforward yet. It’s okay, but I hope development is still occurring to make the product less cumbersome to use (three key shortcuts aren’t really shortcuts in my world—I’m used to cmd+K to paste a link.. not so in MarsEdit).
KerriOnThePrairies about
MarsEdit - for WordPress, Tumblr, Blogger, etc., v3.6.7