i have a debit/atm mc from my credit union....my experience so far is:
during apr trip to south africa/swaziland, only found 1 bank [fnb] atm that i could get cash from....did 8 wd's, all seemed to be very close to the published rates, 4 had $1 fee, 4 had no fee..however, it wouldn't work in swaziland at fnb atm or in kruger at fnb mini atm's.

the card also works as a cc for purchases [but debits, no pin needed] on maestro network [which won't work on maestro logoed atm's w/pin xcept as stated above] & had no problem when used at multiple places. again, seemed to be close to published xchange rate in us papers.

i couldn't get cash at a citi bank atm at nagoya airport, did get some in barbados w/no fees [cirrus network].

recently, w rand @ 6.7 or so, i prepaid for hotels & kruger park for august trip & rate was 6.65 & 6.69, so obviously, no fee [1% would be .6 or so]...i'm quite pleased, but still want to get better atm access overseas. i don't plan to get miles on cc's on the next trip, can't see paying 3-4%..