Dr. Coffee
I think H&S has been mentioned as a 'non-knock-off' brand... 
Still, I think beginners ought to be aware about the trade-offs: You can save some $$$ at the risk of either getting a monday unit, or need to do some tweaks and mods to get the thing to work. Or you can shell out the extra $$$ once and for all and get something that works straight out of the box.
It's a question about priorities:
- High-end brands/models are subjected to intense quality control. There is far less risk of getting monday units.
- High-end brands/models tend to be properly adjusted from the factory.
- High-end brands/models tend to be easier to handle.
- High-end brands/models tend to be better supported in terms of spares, repairs etc.
If the user is willing to accept the associated risks to save some $$$, then that's their decison to make. The crux is that people know the trade-offs.
Apart from that, I'd be interested to know why the people here, who own three or more airbrushes, own that many units. I can see the need for one large-capacity signle-action 'spray gun' for the large-volume work, like hulls of ships, and one double-action unit for the finer detailed work.
But why does one own an airbrush #3?
Of course, I am aiming this in the direction of pointing out the cost of buying two units that does almost the same thing, where the 2nd unit have some extra capacity in one direction or the other. Then I would compare this to buying one (more expensive) unit that does everything the two inexpensive units do.
DoC
All you say is correct. Going with a known brand might be the safest way. No question about it. I suppose that is wise advice for a first time buyer, especially if he don´t have other users around him. But name is also a lot about marketing. The main reason why Iwata is as large brand as it is, is because of a strong marketing of their product. When advicing about beginners airbrushes, I try to keep away from brand-dropping. It´s usually more important to find an airbrush that fits your hand and style of painting.
About owning more than one airbrush. First, I´m a bit of a collector. I like airbrushes, and I find pleassure in buying and testing airbrushes. It gives me as much relaxation and exitement as building models, or watching a good movie. Second, I have a small company that sells airbrushes. Started it only a couple of months ago, so it´s more of a aftereffect from being interested in airbrushes. Third, it can be very handy to have several airbrushes ready, for different uses. This is a reason that I usually recommend against falling for the marketing trick about "2 in 1", several nozzle combos, and so on. In my experience it´s better to have several designated airbrushes than one that you can transform. Partly, because it means that you have to rebuild it between colors, and maybe even more, that I think there always will be compromise when you try to build something that fits everyone.
At the moment I have a bit more than three. In alphabetic order:
Badger 200: Still a good airbrush, but there´s nothing it can do, that others can´t.
Efbe B1: Got this 2:nd hand a few months ago, and it´s a dream when it comes to quality. But it´s seem to need a few new parts, so I can´t really give a complete view of it.
Gunze/GSI PS-275 and 290: My first pistol trigger action airbrushes. Still use them someimes, and can still recommend them.
Grex Genesis XG and Tritium TG: The Tritium is great! Got one of these when I started selling the brand. Fabulous pistol trigger airbrush. The XG is my demo airbrush for the shop, and I´ve used it quite a lot in modelling lately. Good, solid airbrush, that cleans great, and has the best chrome I´ve seen.
Iwata HP-C, HP-CS: The Eclipse is probably one of the best alround airbrushes out there. Modellers can´t go wrong with one.
Olympos HP-100B, HP-100C, HP-102C, MP-200A, MP-200B and MP-200C. All of them are among my favorite airbrushes, but if I could only keep one airbrush in my inventory, it would be the MP-200C. This is the perfect Micron, in my opinion. Best airbrush I´ve ever owned.
Rich AB-100, AB-200 and AB-300: These are among my oldest airbrushes. Got the AB-200 more than 20 years ago. Still a great airbrush. The AB-100 details extremly good.
Richpen 213C / Mojo: Best detail airbrush I´ve ever used. Not that it can make the thinnest line, but it´s the one that can make it from the furthest distance. It must be the combination of the Mike Learn tuning, the needle and nozzle combination and pure luck that makes it what it is. And it works good for larger work as well. Only drawback is that it feels a bit clumsy.
Airbrushes that I´ve owned:
Aztek 470: Hated it. Couldn´t get consistant performance from it. Might have been because it was at the same point as I started with acrylics.
Badger 100, 150 and 175: Didn´t really like any of them. Probably I expected more from them, since I was quite satisfied with the 200.
Fengda: At least 6 or 7 different ones that has come with compressor kits and other packages. Clones of known models. Inferior quality, but usually decent performers. Better than my Aztek experience....
Gunze/GSI PS-269 and 270: Works and funtions a lot like the HP-BH/CH, but has in my opinion better ergonomics. The 0.3mm 269 is probably all most modellers need in an airbrush.
H&S: Evolution Silverline fPS and Infinity 2-in-1: Didn´t like the feel of the triggers. Nice airbrushes though.
Iwata HP-B, HP-BS, HP-SBS, HP-CH, CM-B, CM-C, CM-C+: All Iwatas are nice airbrushes. Sold them mostly because I have others that perform equal or better.
Paasche VL: In my opinion, crude. Really didn´t find anything that made me keep it.
Richpen 033 Spectra / Moflo: Best siphon-fed airbrush I´ve had. If you want a bottle fed airbrush, this is a nice on. As with the Mojo, it is tuned by Mike Learn. Traded it away, and still miss it.
Airbrushes that I will buy in the future:
Badger Sotar. Mostly because I want one for my growing collection. Probably a Patriot or Velocity as well. Mostly because I wan´t to see what the fuss is about.;)
Hohmi/Holbein Y2 or Y3: Have heard great things about these airbrushes.
Iwata CM-SB: It´s the only Micron I´ve not owned or tried. Some artist state that it is the most responsive of the Microns.
Rich RB-2: Very good priced airbrush here in Europe, and it is supposed to be a solid alround performer.
Paasche AB Turbo: True classic. Need to have one for the collection, but it seems hard to find a left hand version at a good price.
Edit: Added a few that I had forgot about, and some that I´m planning to buy. If you have any questions about these airbrushes, just ask, and I will answer what I can.