Core cargo's material is nowhere near as good as the full-whack ones IMO, & the chamois doesn't feel as good. The back of my core ones is going transparent after only like a year, while the other ones are still going strong.
I have the core cargos and am happy with them. I couldn't really justify the extra cost to get the 'proper' ones. Have had them for a while and they haven't gone see-through like others report. I guess YMMV...
Bib shorts for long distance? Are the core cargos any good?