I think, after being a staunch user of the modified dadant for a long time, I'd move over to Smith's.
Don't get me wrong, I still think that the MD is a good hive in these parts and there are a lot of aspects that I like very much however, the smaller Smith footprint, the increased flexibility of double brood/splits above a screen board, the small timber widths when making boxes all appeal. I did toy with the idea of a switch to langstroth but talked myself out of that in favour of a hypothetical switch to Smith's but of course, when you're far down one track it's not easy to change to another.
Short lugs, for me, are brilliant, really dislike the long lugs