Back locks aren't as flickable as compression locks, because they have the backspring tension, which has greater pull than a ball detent. They can still be flicked, though, and especially easier if the blade is a longer one.
Many of the Seki models have slightly 'sharp' holes, but my Golden models aren't chamfered either. Hole 'sharpness' has never bothered me; I've seen a few people post that they thought it would cut them (soft skin, perhaps?), but I've never understood that, nor ever came close to feeling that the hole was uncomfortable. If the hole were chamfered smooth, it would make opening difficult. I have older Benchmade Griptilians with chamfered oval holes that have far less traction during opening.
If you don't like imported Spydercos, or their holes are too sharp for you, then stick to the Golden ones.
Jim