Yeah man, Becker is a total insane sweeper... Sweeping from the 19th position till the 24th fret is definitly crazy ... You don't need only a 24 frets guitar , but you must make sure the 24th fret is pretty accessible too... I've played a lot of 24 frets guitar where the 24th fret isn't easily accessible... I find Jacksons & ESPs better than Ibanez at this point.

Also Friedman's sweeps is realy complicated . Due to his exclusive use of exotic scales in most of his solos, you find lots of legato stuff or even string skipping at the middle of a sweep.

And for Ktulu's sweep , I've seen Hammett alternate picks it on S&M video , and he does it on 3 strings only and a slide ... But personaly, I prefere the sound of a sweep, cuz all the notes sound very even and tight with sweeping.

I don't know what's your definition of (even & tight) , but I know that english isn't your or my mother language ... So probably we're both wrong in expression .. LOL :p

It's a matter of personal taste anyway , but for sweeping you play all the notes with only downstrokes or upstrokes at a time,so they have very similar sound and seems tight to me... That's how I like it.