I've had some Boa snowboard boots, and they've been good, but I've transitioned to non-ratcheting/non-metal quicklace systems. I find them somewhat more durable and easier to make fine adjustments to, while being nearly as quick/easy to use.
Experienced the same. Boa is pretty good, but it seems to tighten almost uniformly along the length of the cable. Which is probably ideal if your boot has a perfect fit to your foot, but otherwise becomes a pain in the, eh, foot. I have problems with pressure on the top of my feet and with the boa system it seems there's either too much pressure there or not tight enough around the legs. Might be resolved by finding the proper fit but laces are really more forgiving when it comes to that.
Tongue shims on your liners might help. A replacement heat molded liner is another option.