I just want to thank everyone for their responses, it's certainly been interesting following the thread!
I guess I fall into the camp that thinks it's a must for the trim carpenter(although a non-slider would work just as well if you could find a decent one these days) and it's very convenient for breaking down long boards or when you need a quick crosscut.
Since I have two of the beasts(along with the Kapex an older(circa 2004) 8-1/2" Hitachi slider) I guess I'll keep them. The Hitachi lives in the storeroom and gets hauled out for outside work, the Kapex resides in the basement in a shop-built cabinet with folding wings and it's own vac. The dust collection is far from advertised but I only have to make a few cuts with the Hitachi and no vac appreciate the improvement.
I asked the question because I was seriously considering replacing the Kapex with the new Makita 10" slider, the one with the front rails. It allegedly has pretty good dust collection, crosscuts the same 12" and would be a new toy. But the more I thought about it and read the responses here, the more I think I'll just dance with the one that brung me. Along with that, I don't have to deal with selling off the Kapex, tinkering with the cabinet and buying a whole new collection of blades. If it ain't broke you don't need to fix it, right?
Anyway, thanks again to all who took the time to offer their thoughts.
Merry Christmas!