Anyone Used REW-Room EQ Wizard?

After getting a new set of speakers "dialed in" to my "man cave", I purchased a new pair of sub woofers for that last octave of bass.

In the past I've had to be patient, integrating a sub with a pair of monitors, to get them to sound "just right", adjusting the positioning of the sub and the speakers, adjustment of the volume, crossover frequency, etc. and eventually got the system to sound right.

With the pair of subs in the "man cave", it hasn't been so easy.  I've tried all sorts of positioning (next to the speakers, off to the side, in the middle of the room, etc.), and have installed eight bass traps so far and the sound is improved, but there are still "holes" in the bass registers, where the volume is highly subdued, compared with most of the bass range, and with some acoustic bass tracks there's still some "boominess" in the room.  The bass traps have dramatically improved the detail in the bass range so far, but it's still "not good enough".

Before I order and install more bass traps, I thought I'd get more accurate "information" on what's going on in the "man cave".  I stumbled on "REW", a program that with a decent calibration microphone (ordered a miniDSP UMIK-1 from Amazon), could give me the info I need to do a better job of improving the bass response.

Any experience with REW and a USB microphone?  If so, any advice?