Drawbacks of using Orb Damage Detect

I'm currently in possession of a map where it will be impossible (<=> too much work) for me to make sure that all spells use scripted damage. Therefore, I'm looking at the old approach: using an orb-ability to detect normal attack.

I know that it can cause the game to break for units with "Attack Ground". Are there any other drawbacks (obviously, I have to script all orbs, but that's not necessarily a bad thing) ?

you wont be able to have that attack missile FX modifing stuff, but that is a minor problem aswell....

Orb abilities suck. Totally. Really, really, really, really, really badly. Blizzard randomly decided to make them no longer work when units autoacquire targets. Something like envenomed spears might work better for that reason.

Other than that, as far as I know you should be fine, but I've got no direct experience with it.

It's just Orb of Slow and (New) Orb of Lightning that behave in that manner. Orb of Frost is safe, as is the old Orb of Lightning and Orb of Venom, along with abilities like Slow Poison, Envenomed Spears and Frost Breath.

I would seriously trigger everything in any case. It's not that much work - hell, I'd find it less irritating than implementing an orb damage system.

Yes, an orb system would be the best choice