It's always been about balance, speed and power, a weapon(Dream of Mirror Gold) that reduces attack speed forces the player to focus their skills toward speed and less towards power, which we see as a hindrance.

It would seem the master weapons would benefit a burst build blademaster moreso then a meele/aspd blademaster, which is fine if you have an infinite source of mp such as a necklace, not even a high level muse focusing their trans solely on a burst bm would be able to keep up.

Its simply a matter of preference to us, we prefer faster weapons so that we can focus more on skills and armor that benefit power over speed in Dream of Mirror. we are not saying these weapons are completely useless, but they do force a change in playstyle because there is no other options for weapons past level 60.

The core difference between a normal aspd bm and a crit-bm is more dex, as opposed to the 30 or so dex a bm normally uses a crit-bm uses 50 or higher. We also tend to use lighter weapons such a a 9-rings or a gold saber, which allows us to focus moreso on using skills and armor to raise power as opposed to skills and armor that raise speed.

The balance between speed and power is a constant struggle, with the only limitations being the aspd cap and weapons available, and of course a -3 or -4aspd weapon being the only option for a high end saber tips the scales rather deeply.