I have the e650, but not the harbeths. I know the harbeths well and I suspect this would be a quite good combination. The E650 has just been great for me.
Im trying out a pair or 30.2s with an E480... sounds great but what I truly need is the 40.2 ... but I prefer a more energetic and dynamic presentation, I found the E650 a little too polite
Don't own the combination, but I don't see how you could miss with it. From what I've read they should have outstanding synergy. But, like I said, I haven't actually heard the combination.