BOA is a tried and proven system.
I highly recommend a dual BOA system so you can get each zone as tight as you want, without over tightening.
BOA works, that's all I can say about it... I own a pair of Vans Cirro boots and they're amazing. It's really nice to be able to adjust your boots while riding.
But they can break... And when they break, it's not like a laced boot where you just toss a new lace on it in the field. I havn't broken one yet, but depending on what you break you may or may not be able to get it fixed at a resort. Busting on in the backcountry would suck.
"When I do good, I feel good; when I do bad, I feel bad. Thatís my religion." - Abraham Lincoln