No pre exists in a vacuum. But that's exactly how some people seem (for purely financial reasons) to want to treat it. ANYthing will sound "alright," even "good," if you haven't compared it side by side with a unit that has a better reputation.
What does "reputation" -- basically word-of-mouth -- matter? Well, you'll always get a handful of elitist twonks that pipe up just to defend their investment, that's true, humans remain humans, but the vast majority are just workaday people like you and me, most of them have been at it quite a bit longer than the average home recordists, and, importantly, most of them earn their living doing this. If that's the kind of advice you want to ignore, you are of course free to do so. Curious about a piece of gear? Do a Deja search of rec.audio.pro or search the discussion boards at Music Player or the RecPit. You'll get the word, and if you search thoroughly you should get enough opinions to decide whether you want to try out the unit at home and form your own opinion.
That's where you make the discoveries -- in your studio, working with the unit, not comparing price tags. You want to know why most studios don't use 100- or 200-dollar-per-channel pres to track most of their main tracks? Rent or borrow a nice box, take it home, and record *several* tracks with each. Create two simple mixes, one with the cheapie, one with the rental.
If you've sold yourself on the idea of doing most of your tracking with the cheapie, and if you have decent monitors, and if you have reasonably capable ears, you're not going to like what they tell you. But let your EARS decide. Arguing about the quality of boxes you haven't heard based on price and ad copy on some internet discussion board is a huge waste of your time.
Yes, there is probably a use for EVERY pre. They're all basically colors, and you're basically creating a painting. Why throw away a color? But most people prefer bright, present colors to that of mud -- though sometimes mud can be used to great effect. It is, of course, a question of personal preference.
Again, you're building a toolkit with which you hope to capture or create great sounds. Do you want to cut corners? Or do you want to go with the tried and true -- if unfortunately a bit more financially painful?
The proof is comparing them side by side in YOUR studio using YOUR equipment and YOUR technique.
The proof is in your ears.
Cheers.