The problem with the off-brand clones (other than the
Altman, which is a high quality
unit which I don't consider a "direct copy") is that they cheap out on things that matter to the longevity of the
fixture. You will find lower quality reflectors, cheaper hardware (nuts, bolts,
etc), and rubber cords in lieu of fiberglass sheathed Teflon high-temp leads. Most of these clones cost around $100 each, in which case I would buy a standard
Altman par can before I'd buy an opti-par, ultra-par, flexi-par,
etc.
It would also be more difficult to source replacement parts for these "clones". You could probably upgrade all the electrics to high-temp standard parts, but who wants to buy a
fixture with the intention of doing this.. By the time you got it to where you wanted it, you had might as well have spent the extra $50 on a
Source Four Par.
As far as light output, I'd say they're OK, but having never done a side-by-side shootout with
ETC's
par, I don't know just how bright they are in comparison. I had a couple of American DJ Opti-Par's (which I believe is the oldest copy), and they were pretty punchy, but the
reflector didn't look as precise as the
Source Four Par. The overall tooling on the Opti was flimsy and undersized and the beam
pattern did seem more uneven than usual. Reflectors are riveted in place, which tells me that the manufacturer considers the
unit more disposable than serviceable.
The
Altman Star
Par, which uses the idea of
ETC's
Source Four Par without blatantly copying it, is most likely a decent
instrument, though I have never seen it in the wild. I suspect the
build quality and parts availability to be good, and the light output is probably as comparable as it's going to get without using an
HPL lamp. If there are any quirks with it, I would suspect them to have to do with the
lens retaining ring, as no manufacturer has one that is super simple to use in all orientations (you have a double
edge sword of needing the
lens to fit securely while keeping the ability to be remove it easily without the use of tools).
At the end of the day, I'd go with the
Source Four par or
maybe the
Altman Star
Par if lamp types are an issue. If you can't afford that, I'd just buy the traditional steel
Altman Par 64.