[sams]

I need to make up my mind bwteen the two of these. I love the amp so I want to pair it with the best fit.

[srb]

I am not speaking from experience, but just from the descriptions and specifications of the speakers.
 
Efficiency:
The VR-33 looks like it would be a better load than the CM9 for your tube amplifier.  The VR-33 has a 90dB sensitivity and an 8 ohm nominal impedance, with a minimum of 5 ohms at 25Hz.  The CM9 has an 89dB sensitivity and an 8 ohm nominal impedance, with a minimum of 3 ohms.
 
Frequency Response:
The 10" woofer + 2 - 6" midbass of the VR-33 allows it to have better bass reproduction than the 2 - 6-1/2" woofer + 6" midrange of the CM9.  The specifications bear this out - the VR-33 is -3dB at 25Hz and the CM9 is -3dB at 56Hz. 
 
Cabinet:
The VR-33 weighs 103 lbs. and the CM9 weighs 59 lbs.
 
 
The VR-33 is designed to be placed close to the wall, which can be an advantage in many rooms.
 
Obviously, a personal audition would be valuable, as you might prefer the sound of one speaker over the other, regardless of bass response.  But again, based on the efficiency and minimum impedance, on paper the VR-33 seems like a better match for a tube amplifier.
 
Steve

[JackD201]

Couldn't have said it better than Steve 

[es347]

I've heard the VR33s with tube amps--the SAS 50W monoblocks.  Fear not. They filled the room (16x24x10) with plenty of well-controlled bass and a midrange to die for....at least for those who don't value life all that much 

[JoeyGS]

And for sure when VR specs are posted....it's the truth and that's how it will perform....even sometimes conservative

[Steve]

And for sure when VR specs are posted....it's the truth and that's how it will perform....even sometimes conservative

I can vouch for your comment concerning specs/bass extension. I tested a pair of 33s at home (thanks Bernie for letting me audition them) with "Pictures at the Exhibition", recorded in Zurich Switzerland using a pipe organ performed by Jean Guillou. The organ reaches down to 16hz in the piece, and although I didn't measure the response, the bass reproduction went way deep and tight. I could feel the vibration on my body even at moderate spl levels. One could easily perceive the hall echos, spaciousness as well so little if any masking.

Highs were similar with very natural timbre of instruments with harmonics reaching the heights.

Albert did a tremendous job designing this speaker.

Cheers

[es347]

Since Steve tends to be modest regarding his creations (SAS amplifiers)...I need to remind all that his tube amps were part and parcel to the results he describes.  Take a bow Steve 

[CGull]

 Where are you located if you like to listen to my VR-33? I own a pair of B&W CM7 I'm using for my rear channels and VR-33 for my main speakers. The CM9 and CM7 are very close sounding in mid range and treble having the same tweeters and midranges , the cabinet and woofer are where the differences.