Thanks for the hate review at snapfiles. It won't increase the chance for DP in XY, but you probably feel better now.
(If you are not luc0815: ignore this post.)
I think 3 out of 5 stars isn't really a hate review. You know, tastes differ...and some guys just prefer Dual Pane.
Some time ago I couldn't imagine to use a single pane file manager. I was very happy with SpeedCommander and DirectoryOpus.
But now I can't imagine to use anything apart from XYplorer to manage my files. Yes, it must be this Zen thing.
I also think you shouldn't implement a feature you don't like yourself, Don. The special thing about XYplorer is, that everyone who reads your forum can see at once, that you want to create a masterpiece. You only add features when you are convinced that they really improve XYplorer without bloating it.
Earning money is important (and DP would very likely bring more registrations), yes, but in the end it's mostly better to remain true to one's principles. To try to make all people happy is very rarely a good thing. If you keep on improving XYplorer more and more users will realize that DP may be a nice additional feature but it isn't something you can't life without.
But if you - some day - think that DP really would improve the XYperience (there may be these rare occasions when it is handy to compare folders visually) and you find a way to integrate it, it would mean that DP isn't implemented because it is requested but because it really is a feature to make XYplorer even better.