I don't know either of them yet, but according to the opinion of people whose ears I trust you should rule out the M-Audio's. The Behringers, OTOH, seem to be a lucky shot: they are considered to be extremely close to the popular Genelec 1031A (others would say: almost a rip-off [;)] ...), costing a fraction of them.
.... being a little bit old-school, I would try to get hold of a pair of used Yamaha NS10s - they sound ugly as hell, but somehow it is still true that mixes sounding good on these speakers translate pretty well on almost any other system.
In the end, let you ears decide. Try to lend a pair of each for a day or two and listen.
HTH,
/Dietz
.... being a little bit old-school, I would try to get hold of a pair of used Yamaha NS10s - they sound ugly as hell, but somehow it is still true that mixes sounding good on these speakers translate pretty well on almost any other system.
In the end, let you ears decide. Try to lend a pair of each for a day or two and listen.
HTH,
/Dietz
/Dietz - Vienna Symphonic Library