i absolutely agree with doug. i have a prs mccarty that i just love. it has become my gold standard for tone and sustain. i also have a schecter C-1 that is a big time sustainer monster. both are setnecks. however, my last project was sort of cross between a LP DC and a prs except that it has a bolt-on neck (my avatar). this thing sustains like no one's business. it far out-sustains any axe i currently have (prs mccarty, schecter c-1, les paul, 57 strat reissue, variax 700, carvin ae185), including those i have built.
don't get me wrong i also like setnecks, in fact, i am currently building one now. i think they are aesthically more pleasing. however, i feel it is a personal preference and has nothing to do with sustain.
i find that i personally like bolt-ons though. in particular, i like the ibanez aanj design. i like the fact that i can change out a neck if it breaks or i want a different profile. as a matter of fact, i had an axe that i built where i wasn't totally satisfied with the neck i made so i made another and replaced it.
take a look at what prs says about setneck vs bolt-ons (click here). scroll down and look at faq #8.
gee, i think this discussion was about the invisibolt bc rich thingy. i hope i didn't hijack your thread. if so, i apologize.