They make some classes simply not enjoyable to play or play against. Slows pierce through SA, stack way too high. Ignore resistances and make some classes impossible to play. They are too easily accesible and leave the use with no gaps. The aoe slows from Guardian, Wizard, Witch, Nova, Zerker and some others should either be removed, reduced drastically. The slows should be moved towards single target and possibly unprotected skills as they used to be. AOE slows are too powerful.

Slows in general still feel too strong, even after the recent changes.

They "nerfed" it to be capped at 50% of your base rather than 50% in total. Most players can easily reach above150% attack or cast speed with Attackspeed/Castspeed Crystals, Alchemy stones, Addons and Class buffs. 

my only concern with this suggestion, are the amount of speedy dasher type classes, which essentially negate slows just for how much they can and how far they can dash.

How about ballancing (IE: nerfing) those classes then? Dashing out from render distance ain't balannced anyway...

The only reason for the slows to exist in the first place, is because they design some classes to be slower in reaction time with less mobility and slower animations.  I feel they shouldn't take away the perks of other classes, just to realize that handicapping certain classes was a bad idea.  One would think they learned that lesson a long time ago with Valkryie.  Years back, they sped up Valkyrie animation times and increased the range of Valkyrie attacks...for these same reasons.  They also added various cancels, to allow Valkryie players to react to combat better.  Then they proceed to create Guardian with many of these same failings, but decided to compensate in a way that proved to be poorly thought out (high damage resistance) and had to revert that perk.  Awakened mage has the same issue I think.  I think the answer is to have a minimum/maximum baseline/standard for animation times, cancels, and mobility.  Every class should be able to move away from impending one shots easily. Every class should be able to react to a grab/CC that they see coming a mile away.  They wouldn't need aoe slows if that was the case. 

Well IDK, but by the time I cast most of my abilities, there are classes that literately can run out from the render distance.

And I (basically) don't have any slow.