+1, I can understand why you wouldn't want people to have guyak speed since maybe they could sprint past all the monsters, and while I don't mind the current walk speed myself it seems like a common complaint whenever I hear about the instance.
I feel like increase agi speed would be a reasonable middle ground between capping the movement speed and letting people walk faster.
I think the most difficult part about this instance is that it requires vocal communication for teamwork, as if your support/phys dps/magic dps gets trapped and can't clear themselves, they need to call and wait for help.
Most other instances which involve teamwork can be completed without any communication by other parties if they know what they're doing and it provides a much more casual feeling when you just do what you need to do well.