+1 for all the people praising Vintage Warmer 2.
I became a huge, huge fan when I realized 1. that the saturation is produces is the most legitimately analog sounding, and musically useful, saturation from any plugin I've heard, including some of PSP's (see my second to last paragraph), and 2. you can crank up the Drive knob and get mixes insanely loud without much fuss or artifacts.
I use it on the master buss usually on heavier rock tracks.. I can get like -8 to -4 RMS levels pretty easily by cranking it, with the Speed knob all the way down to zero and the release as fast as possible (not that I like mixes that loud!). It's like pushing a mix to tape.. it distorts in the best way and fattens everything up. Maybe not a good idea on most tracks, but heavier stuff, yes.
In reality, probably a better idea to dial back a bit, bring the "mix" to about 50% or whatever, but screw it, I say. Even compared to SoundToys Decapitator, which is a superb saturation plug, this thing is more transparent and more pleasant even when in full-saturation-no-compression mode. And as a brick wall, there's no comparison. If you dial in a little bit of normal limiting and a little bit of saturation, this thing really kicks.
Alright, now to describe the saturation.. It sounds less like you're clipping a machine, and more like you're blowing out speakers. The low end always seems to distort first with this thing, meaning your bass can really slice your mix, as if you've simply turned it up too loud for your speakers or headphones and they're driving a little. High end kinda hisses a little through it when you're doing it right, like it's on tape.. but not a harsh clipped white-noise-in-the-background sound, more like a pleasant alteration of the audio. Other sat plugs sound like they're shaping digital clipping.. not this one. Sounds like tape. And that's why I like Vintage Warmer.
EDIT: A word on losing transients, as per ksandvik's post above me: Right on, except for one thing.. I've found with WV, even with the mix at 100, despite the transients literally getting sliced off, things like kick and snare still seem to crack through the mix way more than with other tape saturation plugs like KramerMPX and Reel Tape. My main gripe with those is the loss of transients.. the tendency of the snare to get buried and the kick to start going "blup" instead of "PUNCHYOUINTHEFACE". With WV set to mostly saturating, even though the waveforms are clipped, the snare still sounds like a baseball bat breaking in half. It's one of my favorite things about it.