Dac magic plus

I'm bumping this thread since I just ordered one for my office system. I'm planning on hooking up my MacBook -> DacMagic+ -> Rotel power amp -> Meadlowlark Kestrel HotRods. Will also use my Sennheiser HD600s. I'm going to get rid of my preamp.

Looking for opinions about whether to hook it up via USB or optical, and which is the best cable bang for the buck.

I have a DacMagic Plus in my headphone rig but I am a PC guy.

I've tried USB (with the Cambridge Audio USB 2.0 driver) and coax. I prefer the USB but there's not a massive difference. I am using the Audio Advisor Pangea brand USB cable. Don't have the optical option from my PC.

Going balanced out from the DacMagic to a Burson HA-160 headphone amp. I have the HD-650, not HD600, and find good synergy in this system.

@Dmgoodman, you have a nice rig.
Does the dacmagic gets very hot?

Dmgoodman, is there any noticeable difference when the HD-650 is used with the DACMagic Plus(via its headphone socket) and the Burson headphone amp? Is the difference appreciable or subtle?

Your thoughts are appreciated.