I don't mind the over sized zip ties. They've never given me problems, and I can adjust them by a small amount more easily than normal buckles. On the downside, they're hard to loosen up just slightly, and getting repeatable tightness is problematic. I wouldn't spend the money to replace them.
I don't enjoy walking in my boots regardless, which is why I keep a pair of a lofted booties in my pack. I may look like a dork walking around in booties, but they're comfy and I look like a dork anyway.
Don't ride in walk mode or powder mode. The adjusters can break, and if they do, it can do bad things to your leg.