i have a pair of 603's. i really like them. i use them to record my mahogany Martin and they do a fine job on it. i also use them as overheads, and they do ok at that too.
they DO have a bit of a hyped high end--makes cheap cymbals sound cheap--thin, harsh and brassy. i compensate by using darker cymbals (zildjian K's, which i like better anyway). the 603's might also make a really bold, boomy acoustic with new brassy strings sound kinda crapulent, too. although, i DO suspect that between a pair of 603's and a pair of MC-012's, you'd have your bases covered for a while.
the V67 got a LOT of great press (and hype) on this board when it came out (and then again when the price fell below $100). since then, people have fallen out of favor with it somewhat. a similar thing happened with the Studio Projects C1. Mainly i think expectations and the overnight "wow factor" came back down to earth somewhat. still, i can't imagine it's a "bad" mic for $80, especially on the right source--could be a very flattering vocal mic on the right person, or sound great on the right guitar. mind you, i've never used a V67, so i can't give you my personal opinion, but i CAN say that my desire for one has waned a considerable bit given the reviews of late.
plus i must be one of the only folks who thinks the V67G is UGLY. in all honesty, most of my remaining desire went away when i saw the mic in person for the first time--could they have picked a nastier looking split-pea-shit green color? it reminds me of something you'd find inside a diaper. and the gold looks all manner of cheap. granted, looks ain't everything, but when we're talking blow $100 on a V67 versus save it for an AT 4033 or 4040, looks DO matter--especially when it's "new kid" versus "proven winner". i was ready to give it a whirl and see if it worked on my voice up (nasty high-end be damned!

) until i saw it in person. maybe if i found one of the black ones instead...... :b
i've really wanted to check into the V69 and V77, but haven't had the time.
cheers,
wade