Well, I would say, some extra spaces usually cause less harm, than directly joining different words (at least in situations I normally use this function). But surely there are also uses, when a pure join without spaces would be useful.
The best in my opinion would be an option to choose a separator before joining lines (if it won't be too complicated to code). -- <http://forum.pspad.com/read.php?2,39067,39074> PSPad freeware editor http://www.pspad.com
