cantoresq: There is a very simple difference between nussach and trop, namely that there are certain parts of the nussach that are left as — to misappropriate a computer term — user defined, such as Kel adon. Kabbolas shabbos should definitely count as one of those considering that the nussach you are so concerned about is actually older than the tefillah itself!
I find Carlebach kabbolas shabbos very moving, especially after a long week. The only problem is that some people, particularly young guys who are not used to kabollas shabbos being lively, get carried away with having a good time and ruin the mood for the people who come for dvekus.