As far as immediate corporate value, it's definitely worthwhile....same with a Gulfstream type. I really doubt it means anything to any airline though.
Even if you want to go the Southwest route, the 737 type isn't necessary until you get hired. And then you can do it for relatively cheap and quickly...definitely vs Gulfstream/Global.
As for Global work vs 121, it's been talked about adnauseam around here.