I certainly do not consider myself a power user and I don't use a full-fleged DAW, but just a plug-in host. Rig consists of:
Hardware: Yamaha MODX 7, Studiologic Numa Compact 2x, Casio PX-S3000, Behringer XR18 and a MIDI Expression Quatro.
Software: Cantabile (plug-in host), Assorted VSTs. X-Air Edit (Behringer XR18 control)
All three keyboards and the Quatro use USB for MIDI communication. The MODX is the only synth that is using internal sounds. The Casio and Numa are used solely as controllers.
The Behringer can be used as an 18 x 18 audio interface. Using Cantabile, I can route each VST instrument to it's own seperate output on the mixer and control level via the X-Air Edit app.
The Quatro connects up to four expression pedals via a single USB and then using Cantabile route to the various keyboards/plug-ins as needed.
The MODX is the only keyboard that I take an actual audio signal from and route that to two inputs of the Behringer. I'm guessing that if I attempted to use ASIO4ALL, I could eliminate this connection, but I kind of prefer having it as a safety net.
Cool Stuff About This:
Can actually route analog audio through VST plugs. For example: MODX organ preset through IK Multimedia Leslie.
Various VST plug-ins levels can be controlled level-wise from the mixer app as if you were controlling faders on a mixer.
Not So Cool Stuff:
Reliance on a computer.
Ground loop/Noise issues become a lot more complicated when they involve USB. Especially if the computer used is a laptop or utilizing a laptop chipset.