Oh, come on!
It's not even in the same galaxy with a Malkoff or HDS.
Aside from being much better in every possible facet of construction and operation, the Malkoff and HDS actually have proper thermal design(gasp! Imagine that!) without any need for stepping down the output to avoid burning up the LED from poor design.
It's a lot cheaper to program the chip to turn the light down lower, and slap the guts into a housing that they don't have to worry about fit and function, than it is to make a proper flashlight design with thermal pathways in the design.
All the mass produced Chinese lights do this, so they can slap them out by the millions at low manufacturing cost, and charge a lot of money for them over here in the US.
The whole comparison is just silly, IMO.
There is no comparison.
Sorry if this sounds harsh, but it's reality.
I don't mean to offend anyone, so just call it "my opinion".
Let's agree to disagree. Here are some facts to back up my viewpoint. I'll use selfbuilt's review of the Viking Pro (and I'll try to focus most of my comments on that model, if I can), as that's the light under consideration by the OP. I hope this (brief) comparison is useful to the OP. The Viking Pro review can be found here
http://www.candlepowerforums.com/vb/showthread.php?366051
First, let's address the claim that Armytek doesn't have proper thermal design, and has a "need for stepping down the output to avoid burning up the LED from poor design." Simply check any of the regulated-runtime graphs in the review to see that this claim is plainly false. (To be fair, selfbuilt reported some strange behavior for 2 x CR123 primaries on the Viking Pro, where he observed STEP regulation when FULL regulation was selected. I'm not sure if he came up with an explanation for this, but if FULL regulation is important for use with 2 x CR123, then this light may not be a good choice. But to say that there is a "need for stepping down the output to avoid burning up the LED from poor design" is clearly false, as the light is shown to be perfectly capable of FULL regulation, with no signs of damage to the light.)
Next, let's address the claim that Malkoff and HDS are "much better in every possible facet of construction and operation."
Let's talk about operation first in terms of UI. The claim about operation (UI) seems silly to me, as Armytek's Pro models (including the Viking Pro) can be programmed to have a staggering range of settings. In fact, it is possible to copy exactly Malkoff's "tighten head for high, loosen head for low" UI. If the user doesn't like using head twists to change modes (not just lines - or sets of modes), simply opt for the Basic version instead of the Pro for a no-nonsense UI without any complications. If the quote refers to Malkoff's 361 UI, for example, then the Basic Armytek models offer a similar UI in the head-loosened state. As for the HDS's UI - that's another beast altogether. It's true that the Viking Pro doesn't have anything similar to the Rotary, for example. Other than the rotary, however, the Pro models are able to be customized to arguably the same extent as any other HDS (each has features the other doesn't, and both have tons of options!).
The next part of operation - things like how a light feels in the hand, how fluidly the UI itself works for a particular user, etc. - is largely subjective; I'll just say that I have no qualms with any of these manufacturers.
If you look at operation in terms of performance - things like output and efficiency - the Viking or Predator is going to blow many of Malkoff's offerings out of the water in terms of both total output and lumen-hours, and Malkoff simply does not offer anything with the throw of the Predator (including the Hound Dog, to my eye - though that may change if he offers an MT-G2 version in the near future!). If you further restrict yourself to the same size class, Malkoff will have trouble keeping up with the Viking in terms of both output and efficiency. See selfbuilt's review for specific comparisons between the Viking Pro and other well-known lights in a similar size class. At the other end of the spectrum, the Viking Pro claims 130 days of runtime on its lowest setting, which I believe outlasts current HDS low settings (of course, this isn't a very fair comparison - 3400mAh vs 1500mAh - but I believe the Viking's lowest setting runs for several times as long as the HDS's lowest setting) and many of Malkoff's stock options (maybe a 361 on low with a high/low ring would be in the ballpark?).
If you include, say, durability in the discussion of performance, then all three brands are known to stand up to some pretty heavy abuse. I believe torture test videos are available online for all of these manufacturers.
Finally, as far as construction goes, this is largely going to be subjective (as will part of the operation of the light - preferring electronic vs clicky switches, for example). Armytek offers thicker coatings on their lights, and pots the electronics (just as Malkoff and HDS do). As I said before, Armytek lights FEEL very high-quality to me when I hold them - just as much so as Malkoff and HDS lights - but this is clearly an opinion (for what it's worth, selfbuilt also comments that Armytek's lights seem to be of high build quality). There are probably too many design implementations in HDS lights to even discuss, and I would imagine that a detailed analysis would leave HDS as the clear winner in terms of thoughtfulness of the design - over both Malkoff and Armytek. (If you go to Armytek's website, navigate to the Viking Pro, and click on the Specifications tab, you'll see that Armytek really has put a lot of thought into the design - it's obvious from all the features they list.)
The rest of the post seems to be subjective comments about the light based on its location of manufacture. I don't think there's any point in attempting to address that part of the post.
For what it's worth, I own lights from all three of these manufacturers - and will continue to do so! But I want to make sure that the OP has accurate information in order to make an informed decision.