While the active skills end up fairly similar, have to remember that Manticore is pretty trash in general for pet builds other than the RR. If you put all 6points in it, you get 60% poison damage(only good for bigboi build), 2%OA and 5% health, and the devotion itself only gives 1green 1purple back. Meanwhile for 5pts in Bysmiel, you get 70% damage, 8%total speed, 20vit resist(not great) and 10% health, and you get 3 greens back on top of it. Plus an additional pet offers an additional target to soak up damage/block monsters.
Downside is the bysmiel pet isn’t permanent, so you do drop the RR sometimes while manticore is virtually permanent. The pet also reduces OA by 180 though, which is a fair bit.
So overall, it’s pretty good, especially in terms of devotion points.
Going by sheet DPS on my lightning AAR Mage Hunter it has to be closer to 15% than 25%. The sheet DPS is close to what I had prior, 105k now vs roughly 115k before. Not sure how much the change of Maiven influences that, cannot remember how much it reduced damage at somewhat overcapping.
Edit: Just checked, Maivens was and still is at exactly soft cap. Think old damage reduction at 12 was -7% so 2% more damage I guess?
I find it more baffling that they still try hard to sell Reap Spirit for Spellbinder builds, even though that stretches it really thin and the bonus from the various pieces from the set and Aetherreach do not make up for all the points you lose in other skills for what exactly? A pet for which you have no bonus, does not deal a lot of damage and interupts AAR channel.