Sorry Matt ,
I originally thought it was Robert , but then remembered he had the pmc,s so then your name popped into my head .
A JM Labs fan I see (or are you just plugging the name?)
Just plugging the name , Tim
Sometimes I love them , sometimes I don,t .
I,d quite like to get my hands on the 907be or the micro utopia be , but I think it,ll be a while before I get a chance .
If your short of funds , then the homemade air plats are worth a try . I think they,re a must with wooden floors , but not so necessary with concrete floors .
I also think you get a cumilative effect with them . The more kit you have on them , the better .
If you,ve seen my website , you,ll notice I used them under everything .Even one under the Hark rack .
I,ve got my hifi in the living room these days (smaller flat and concrete floors)so I don,t use them any more .(The misses wouldn,t want them in there

)
Single tube air platforms perform the best (really wobbly) but you can still get good results with 2 tubes in a platform (far more stable)
And of course the good news is that you can make them for as little as a tenner each (basic design)
I,m not going to comment on the sound , as you know it,s not PC to comment on this sort of thing
The simple fact is , they,re so cheap to knock up it,s worth trying (especially if you have wooden floors)
Under the speakers first , then cdp , then amps ......
If you like the effect , then you can either make some nicer ones or buy some siesmic sinks.
atb
richard.
ps ,
the sound ...... well it,s a bit contradictory .
the sound definately seems to feel more relaxed , but your also aware that the music is more dynamic , and you get a bigger soundstage ,so like I said contradictory.