RME ADI-2 DAC FS is it "All That", especially for under $2,000?

+ I need to connect 2 Macs, but there is only one USB socket. I am thinking about 2 possibilities. I already have an external USB to SPDIF converter (a Hag USB), so could connect one source via Coax. Alternatively I get a hub, to connect both sources to the one socket. I do not want to degrade the sound and ideally would prefer not to have to switch between the two sources on the hub.
Thoughts?

by the way, The RME feeds into a Pimare P30 pre-amp via balanced connections, in stereo bypass mode (so there is no reconversion to digital). I have active monitors, so everything has volume control.

I think you would want a USB switch instead of a hub. With a switch you can connect multiple computers to  multiple devices a hub you connect 1 computer to multiple devices. 

thanks. yes, i should have said a USB switch. presumably any of reasonable quality should suffice?

You just don't need to pay this much for what the RME does, unless you want its EQ capabilities for some reason.

Otherwise save your money can get superior, measured performance with the new Topping D90, which uses a latest generation AKM chip.

Yes, I thought about that, but for the extra there is some flexibility for room correction etc. I´ll get round to that once I´ve figured out the basics. And it´s German, for what it´s worth.

Although it sounds incredibly clear, when the volume is set in mid-range there is more audible white noise from the monitors, more than with the old DAC which is inside the pre-amp. Is there any reason why I should not set the volume to maximum and attentuate through the pre-amp?