Thought I'd chime in here as I just got my HMG in today. As of now, I've owned three of the more prominent synthetic Korean bows: SMG, YMG, and of course now the HMG. So here's my comparison:
SMG: Actually was the first Korean bow I bought. I sold it but actually miss it till this day. I think SMG is a tremendous value for the money plus there's a lot of precision/QC that goes into the end product. I'd agree with the prior reviews I've read here and ATARN that its probably one of the if not the fastest of the Korean synthetics. It is not necessarily the most cosmetically pleasing but they do a good enough job with the synthetic covering so its tasteful enough and close enough to the aesthetics of a true horn composite. The major con I found with it is I don't care for the monofilament wrapping above and below the grips. I found that it could come apart too easily if one occasionally made shots where the vanes would braze the wrapping.
If SMG would change the wrapping material it would easily be the best out there, particularly when factoring in the low cost of the basic carbon SMG.
YMG: Likewise alot of precision/QC in the final product. And yes its the most cosmetically close to the horn composites plus the grip is more delicately defined and superior wrapping material is used above and below the grip. Its very fast like the SMG, though some express the opinion that they found the SMG faster. I can't say scientifically one way of the other since I have never chronographed the bows but typically, you buy a bow like the YMG for its finer qualities particularly in the superior materials used and of course the fact that it performs extraordinarily well.
HMG: After setting the bow up today, I can honestly say its a happy medium to what the SMG and YMG are. First, the cosmetics are so-so and some precision is lost it seems, particularly with the leather bow nock covering. The leather doesn't appear as stretched out tightly as it could over the nock and so a bit of it actually sticks out at the tip, not fully flush against the surface. So it has a rather crumpled look to it. I also don't care too much for the spiraled patterns on the synthetic covering or the color of the synthetic covering, its somewhat gaudy. Some assembly is required too for the bow as the grip material comes to you unattached. You'll have to cut it into appropriately sized strands and wrap it around the grip your self. I spent the morning doing that and used contact cement for the adhesive. It turned out rather well, and its not uncommon I know to have to do this for a grip of a Korean bow but nonetheless its an extra layer of work that is required which the SMG and YMG don't.
Some of the material I'm really pleased with though and actually find it quite exceptional compared to the others. For instance, good string wrapping is used above and below the grip and at the siyah transition areas. A very nice piece of what appears to be synthetic leather is placed for you at time of crafting based on whether or not you intend right handed or left handed use. Its well placed around the side you intend to shoot and very sturdy, well glued etc.
Regarding performance, both my SMG and YMG were 55 at 31 inches. I bought the HMG at 45 at 31 so I can't say for sure if its 'stronger'. Its certainly supple though and even at distances of 30 yards away from the target there really isn't a difference in drop off compared to my heavier YMG or SMG. Its fast enough for its draw rate as I can honestly say I've had a synthetic Tatar bow at the same draw weight from a rather low grade company that was pathetically sluggish. So even an average Korean synthetic bow will easily out perform any of the other synthetics on the market, particularly the lower grade companies as I like to think of them.
I'd say its a pretty decent value for its sticker price, but its overall not better then the YMG or even the SMG particularly value wise for the later. At 280 USD, it comes with string, and grip wrapping material. At 200 USD, SMG gives you its base carbon bow with two strings and a bow bag and bow sock. Only aspects of the SMG material are somewhat lesser compared to the HMG but truthfully, you could always purchase some type of leather that's malleable enough and glue it around the monofilament wrapping of the SMG and you'd be just as good to go. 
