Audiophile

JRMC has a feature rich interface.
This in general doesn't appeal to the audiophile community.
There is a strong belief that less is more (sound quality).
However JRMC offers a couple of typical audiophile options.

Drivers

MC15 adds Kernel Streaming

ASIO

The Audio Stream Input/Output (ASIO) architecture is developed by Steinberg to create a low latency, high performance, easy set up and stable audio recording environment.

It is a proprietary protocol.

Your hardware must support it.

Direct Sound

This is the Windows default.
It allows multiple audio streams and they will be mixed and converted to the same sample rate.

Disk Writer

Writes the audio to Hard Disk.
Audio is converted to WAV.

Wave Out

The old Windows default (3.x).
It has been superseded by Direct Sound most of all to improve gaming experience.

Kernel Streaming

Compared with wave out method, kernel streaming requires less CPU time.

It also bypasses KMixer and Windows volume control.

It has a lower latency.

This might be interesting when using XP.
XP can be configured to deliver bit perfect output but this is probably a better way as no other device can use the sound card during playback.

It probably won't work with Vista or Win7.

Kernel Streaming is known to work on certain Windows Vista and Windows 7 configurations, but not with devices having WaveRT drivers such as High Definition Audio Devices integrated with newer motherboards

http://www.hydrogenaudio.org/forums/index.php?showtopic=78885

In my case (Win7) it doesn't, no output device is selectable.

WASAPI

A driver available in the new windows audio architecture (Vista and later).
In exclusive mode it bypasses all the mixing, sample rate conversion, etc normally applied by Windows audio engine.

In the Windows sound panel Exlusive control must be checked.

More on configuring WASAPI can be found here.

Can you play this from memory?

The answer is yes.

You can choose to load the entire song in memory, no disk access during playback.

Multiple output devices

If you have multiple audio channels e.g. the onboard speakers and a external DAC, you can set the speakers as the default playback device and Media center to the external DAC.
No more system sounds in full blast over the stereo!

Headphone

What sounds good over the speakers often sounds very much like STEREO over the headphones.

Using a crossfeed can make listening using headphones more agreeable