Hola Eric,
It's getting better (once again, I'm not sound engineer but just an attentive listener) but it would seem that the trick would come from the mix itself :
In your different mixes, the high mid and high registers tend to encroach on the correct mid and low registers ; those treble "are eatening" the right space of the medium register and even the bass which has to give the pulse is affected.
In the Bob Katz mix/master, everything has its own place : the high register is tamed to leave the solo instruments express themselves, and the high mediums (and "bad" mediums) of the solo instruments are tamed (or removed) to give space to the bass : in fact, this the bass which is the fundamental establishment of the mix : the bass confers movement/groove to the track
Now, it seems to be obvious that there is an "effect" on the bass in the Bob Katz mix (like Renaissance Bass from Waves): it is as if the sound of the bass would "bounce" and adds life to the track. In comparison, the bass in your mix may appear to sound "flat", we hear it but it doesn't enhance/emphasize the piece.
I am in learning curve concerning the mixing sound techniques, and ... pfffff...; it's rather complicated !
So what were the techniques Bob Katz used to TAME the disturbing overlapping frequencies in order to air the mix and get a f*** well balanced mix ? Have we to search towards the control of the attacks/transients and the decay of the elements ? ( Is this that which is called "enveloppe" ?) What tools allow that ? : compressors, transient shapers ?...
One question : Has Bob Katz worked with the individual tracks or just with the final mix ?
If he worked with the whole mix, he is very skilled and has high quality materials .
What plugs in in Sonar or from other company is able to give gentle separation among the distinct frequency regions and is able to air the mix ?
A multiband compressor ?
An esoteric tool like Kush Audio ubk ?
A clever combination of EQ, compressor, vintage plugs, stereo tools, psychoacoustic effects, enhancers... ?
Concerning the work on individual track, every sound mix experts insists on the necessity to clean up every track with radical high pass (with a slope of 24/48dB min) and EQ adjustments :
I don't know if you understand French language, but there is interesting tips and tricks given by a guy called Cybertrech with his tutorial videos in particularly here :
http://vimeo.com/10091391 Eric, let me know; we keep in touch
Pierre