Caltrops and Spiritual Radial

Is it worth it to take the Radial branch of Spiritual for Caltrops? I've already got slow enhancements to get it to 95% slow (91% after ED). I know there's a cap to slowing enemy speed, I'm just not sure if I've hit that with or without Spiritual Radial

So should I take that or go for the Core branch? This is for a Bots/Traps MM

If you have 91% slow enhancement in Caltrops, it will reduce enemy movement speed by about 152%, right? Their speed bottoms out at -90%, so if you account for the Purple Patch, your Caltrops alone are already enough to floor anything +3 or lower. With the alpha level shift there are very few enemies that are +4 to you anyway, so you'll rarely benefit from the improved slow. On the other hand, if you do take the Radial path, you could free up a slot or two in Caltrops to use elsewhere.

I see, thanks, I guess I'll be going Core then