Well, today I got my ES335 back from a local guitar tech, with my new Bare Knuckle Stormy Mondays AIV on!!!

I haven't played with them more than 1-2 hours so I'll try to share with you my first impressions:
The first thing that I noticed was that the sound of my guitar became more open sounding (with less midrange) and with more acoustic character :)
The balance between the 2 pickups is now excellent in comparison to my previous (Classic 57 pickups). Now I can switch between the 3 positions and have an even sound as far as output and frequencies are concerned...
I loved this from the first chords that I tried on the guitar :)
I liked very much the detailed sound and the response of the 3 high strings. Crystal bright, without any harshness!
And now the "bad" news:
I didn't like very much the response of the lower 3 strings...They sound somehow rounded and they have not so much detail like the higher 3 strings do have.
Also they are less percussive compared to the sound I had with the Classic 57s...
Fourth Feline had mentioned earlier on this thread:
You will notice a precise , firm but pleasant presentation on the top three strings, but you will also notice that when he hits the bass strings, they lack the authority / detail of the top three strings, almost like someone has reduced the volume on bass notes - and increased it on treble notes.
and I think that this is the best description of the SM sound on the bass strings.
I don't know if this is in my mind, or if I'll have to experiment with the pole screws in order to get them right, but I didn't like much that...:(
Also, I am not yet sure if this is good or not, but the SM AIV sound pretty compressed.
When I tried them at first on my Fender Hot Rod Deluxe, I had the feeling that I was playing with a compressor pedal on.
Maybe this characteristic will be helpful in a live situation, but I am not pretty sure if I like it or not...It sure felt strange when I first heard it...
That's enough for now :)
I'll try them more, and experiment with their heights in order to find their "sweet spot" and I will return with a more mature opinion about them ;)