Don't know how this happened (lol) but I ended up with 3 calibrated measurements mics.
First, the Umik-1 that came with the MiniDSP C8-12 DL DSP (original cal file)("free" because it came with the DSP or $110 if bough from miniDSP or PartsExpress), then got a Umik-2 (original cal file) ($236 shipped from PartsExpress) and finally a Umik-1 from Cross Spectrum Labs (that I also downloaded the original cal file from miniDSP) ($120 shipped).
Since I had them all here, I decided to perform a not so scientific test to try and measure if there are any difference in what they measure.
Setup: Decided to measure the center channel of my Onkyo home theater which is supposed to be THX certified. Made 3 measurements with each mic. Measurement 1, near field from the tweeter. Measurement 2, near field from the midrange. Measurement 3, 1 meter away from the speaker. Used REW sweeps and 1/3 smoothing.
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Now on to the graphs.
First one shows the 4 measurements near field from the tweeter.
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Second graph shows the 4 measurements near field from the midrange.
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Third graph shows the 4 measurements 1 meter away from the speaker.
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Last graph compares the Umik-1 I got from CSL using both cal files (the CSL one and the miniDSP one).
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Some conclusions:

1. All mics are almost identical from 3-400 up to 7-8 kHz.
2. There's a bigger difference between both Umik-1's with the original cal files, than between the same one with the CSL vs original cal file.
3. The Umik-2 starts to roll off first and has the biggest drop at the higher end of the spectrum. (Might be because of the bigger capsule?).
4. You get a lot of "bang for the buck" with the CSL mic. Not only do they cost basically the same as a regular one bought from miniDSP or PartsExpress, but you get an extra cal file (0,45 and 90 degrees) and the certificate that its calibrated against another mic.
5. Umik-2 is twice the $ of Umik-1. Is it really worth it? From this simple experiment, not really. But still need to put them to the test with Dirac in the car.

J.