Men's Vogue definitely fills a void in American men's magazines. The Vogue worldwide empire prides itself on excellent reporting and pretty impeccable taste. Vogue Uomo and British Men's Vogue have been cultural touchstones for at least 15 years, while America had only GQ. Not such a bad thing, but some time in the last decade GQ has tried to shed any trappings of a "gay" aesthetic or sensibility; there are times when it seems like a Maxim with better clothes.
I get both GQ and Men's Vogue, among others; the clothes and fashion advice aren't terribly different between the two. But while GQ beats its chest and makes sure that there ain't no fey vibe to its features (interestingly disdaining just that very sensibility which gave it the gravitas it currently holds) Men's Vogue couldn't care less if you are gay, straight, metro, uber-- whichever social role you care to self-assign-- as long as you are concerned with au courant fashion, art, design, and style.
If I had to choose one, I'd go MV.