They solve different parts of the same audio chain.
Wave XLR MK.2 is where a microphone becomes a signal at all
An XLR microphone is a passive device; it needs phantom power
and a preamp before a computer can hear anything usable from
it. Wave XLR MK.2's 80dB of gain and 24-bit/48kHz monitoring
path is that preamp stage, plus Wave FX processing (compressor,
EQ, voice enhancer) applied to the signal before it ever
reaches your recording or streaming software.
Mix Create is where multiple sources become one mix
Once a microphone, game audio, chat, and music all exist as
separate sources, Mix Create's 4 knobs, 4 mute buttons, and
5-inch display give you physical control over each one plus a
dedicated submix button for a separate stream-facing balance.
Tom's Hardware called the customizable mixes "excellent for
content creation," but that only matters once you have several
sources worth separating in the first place.
Buying the wrong one first solves nothing
A brand-new XLR microphone plugged into Mix Create produces no
audio at all; Mix Create has no XLR input, confirmed directly
by Tom's Hardware's "no XLR support" con. Conversely, Wave XLR
MK.2 alone won't give you a physical mute button for your
Discord channel or a separate stream mix; that routing lives in
Wave Link's software, not on hardware knobs.
The realistic end state is both, in the right order
For a serious streaming desk built out over time, similar in
spirit to layering peripherals the way an
OSRS setup adds pieces one at a time, Wave
XLR MK.2 solves the microphone signal chain first, and Mix
Create solves routing once there's more than one source to
balance. Buying them in the wrong order just delays whichever
problem you actually have today.