Makes sense, however for my build i plan on keeping IK Helm and Chest for the 60 AR Bonus. I currently have the IK Boots as well and will sell it once i find a decent ice climber piece.
IK Helm IMO is a no brainer since it has high str, life%, socket, damage reduction and 6% crit. It's the piece i chose in combination with IK Chest since its currently the best chest piece in the game.
For the lacuni, i accepted the fact that primary stat, aspd, crit, AR is out of the question. Though its the best roll combination out there, i'll just find something with stats that matter and make it up elsewhere.
Regarding 12% vs 24% movespeed, i would really want to have the later, and hopefully when im able to get enough gold to afford the ice climbers boots, the price may have gone down for the ones with Movement Speed. 12% should be the minimum for your character.