I agree, Vengeance effects vol 1 is the bollocks, along with Vengeance Essential clubsounds (for kicks etc) alot of sample packs contain some great stuff, but also alot of shite, really take your time choosing unless u've got money to burn.
I while ago i bought the full cycle sample pack, it was the worst decision ever !! WOUNDED....
Sinse then i dont really buy sample packs anymore, but i do think they are an essential part of learning to produce, ive only been in the game for a year and tend to steer clear of them now, i still buy sound fx packs though always come in handy.
I use a lot of samples from the computer music free cds. a lot of them are not drum and bass orientated but i quite like that as you can get some different and obscure sounds from them that sound good.
Apart from snares and kicks of course. Although they did a drum and bass special about 2 months ago that had some badboy drum and bass drum samples.
steer clear of the many hip hop sample packs out there.... most of them are absolute shite, just a bunch of random crappy drum sounds thrown together, maybe some eq and reverb on top (which is not something you want anyway), you may find the odd usable sound but you will be mostly dissapointed
cant comment on the hypersaw pack... but the breaks packs are all breaks sampled from old records.... so no.... damn fine packs though, ok its not really in the spirit of crate digging but certainly speeds up the creative process