It's all a matter of expectations.
I don't think you should look at research chems as "replacements" of the "originals".
Recreational drugs as we know them (ie the ones that have been popular in the last 30 years) are the result of a number of coincidences and historical quirks.
Why wouldn't I want to try psychedelics unheard of since the 1960s that never circulate on the Australian black market?
Why do people worship MDMA as some perfect drug for example, yet pure mescaline is incredibly rare?
There are a lot of exotic chemicals out there that niether hit the black-market mainstream, nor became available to consumers via research chemical vendors online.
As for the supposed illegality of analogues; we are yet to see these laws enforced very much in Australia. Not for importing or possessing quantities for personal use, anyway. Charges for small quantities are very rare (to nonexistent, to my knowledge)
Sure, they'll get confiscated by customs, but so will pirated DVDs.
For people who have better things to do than chase up dodgy hook-ups, a bit of judicious internet research can turn you on to all manner of interesting things. Most of them are extremely cheap by Australian standards too.
I hate MDMA so I'm not interested in finding a research chem equivalent, so perhaps it is a matter of taste.
I think the idea that research chems exist to replace or outdo the more established, well known recreational substances is the wrong way to approach the whole thing.
This is fine however - I think the fewer people taking RCs the better, frankly.
The thing Ive really enjoyed, in my brief period of experimentation, is to explore some novel tryptamines (agreed with jones-in, 4aco-dmt is a fave) and try some classes of substances that I've never had access to previously.
I don't mix in heavy drug circles; most of my friends are musicians, artists, academics - people who might take drugs, but very few of my friends sell them nowadays.
I'm not a raver, I don't dig the "party scene" and my energies go into other pursuits - not necessarily ones that open up my access to drug contacts.
In taking the plunge with cautious exploration of research chemicals, I now have access to things I've only dreamt about before. I've been able to develop a stash which I intend to have onhand for years. I wont be guzzling grams at a time over a weekend, but I like having it quietly stashed away for when I might need some.
I'm not interested in trying to convince a dr that I need benzos, but I like to have some onhand for comedowns or stressful times (like the funeral I went to yesterday). I'm not going to become addicted to them, I don't find them recreational, but I like to have some onhand, just in case.
Same goes for stims- I don't take them recreationally more than a couple of times a year anymore, but I find it very convenient to have them around.
If I'm moving house, for example, I like to be speeding off my chops while I pack up my stuff, but id rather not pay $xxx to do so.
Drugs are very very expensive in Australia, and usually pretty cut (depending on what you are getting). I dont like spending all of my expendable income on drugs, it has never sat well with me. There are plenty of other things I would rather use that money on, but I still like to get high, when I get the urge.
For the sake of curiosity, I have found some research chems to be very useful. I don't take every new substance on the market, I don't take drugs with the expectation that they'll replicate some other drug, and I research things very thoroughly before I even think about ordering them.
No, there aren't many that perfectly replicate the stereotypical illegals, but some of these drugs have different qualities of their own that make them very interesting and even beautiful. I have not yet tried the NBOMe series, but a lot of reports have described them as similar to LSD but a little less physically taxing.
To see them as a "legal" or semilegal replacement is the wrong way to look at it, in my opinion. A lot of these drugs are new substances, and it is ignorant to presume that they are nothing more than a substitute of illegal drugs we are already familiar with...which is a big reason for some people running into problems when they take MDPV as they would consume meth, for example.