I'm sure there is a thread on this somewhere, but I'm on my phone and it's a pain in the ass to search...
Anyway, I just got a pair of Ride boots with the boa laces. I haven't worn them yet (this weekend!) but a friend has already told me to take them back because of the laces. It's not anything on the brand of boots, just that she doesn't like the boa system in general. Something about them needing to be re-tightened a lot.
I just got some boots with the BOA system back in November. I have ridden with them 6 days. I find myself adjusting them more than I did with my laced boots because it is easier and takes less time to make adjustments. Before, I would endure whatever discomfort I had until I made it to the bottom of the hill. With the new boots I can stop by the side of a run and spend a few seconds twisting, tightening or loosening without having to retie lace knots.
So far, I prefer the boa system.