WaveRT stands for Wave Real Time and is Vista's answer to a built-in, high performance, professional audio system for the purpose of multitrack recording and low latency.
Mixcraft supports WaveRT. You will also need to have a sound device that has a WaveRT driver, otherwise it may just be in compatibility mode and not receive many of the benefits of WaveRT.
I got me an Echo Mona and have Vista.
I now Wave RT as an option.
Just did a quick sound check with all 4 mics simultaneously.
No problem.
Is it better than Asio?
The Mona Console shows that it has switched to 48 kHz to match the settings in my Preferences so I'm guessing that I'm not just in "Compatibility Mode" but am wrong much more often than I'm right.
Just the kinda guy your stuff was made for.