You would have to show me this because I don't see it. Hot Toys Mannequins are better for articulation, but break as much as Medicom's. So they pretty much even out there. And if the new Prometheus body is a high-quality item...the advantage gets tipped toward Sideshow.
It has been stated that we are looking at a 120.00 price point so cost is an even playing field...no winner. But you have to take into consideration that at 120.00...Sideshow could add a lot to their figures because we are getting awesome figures for at least 30 dollars a figure less than that right now. Think of the improvement Sideshow could make at an extra 30.00 per figure. Of course, Hot Toys Predators are the ones that are 120.00+. The Human figures like the Colonial Marines were down around 90.00 if I remember correctly. So Hot Toys would have extra funds for developement as well. So maybe Hot Toys could edge out Sideshow on that one.
Sculpts and paint apps are a matter of preference. I do not care if mine look like the actors, but I want them to represent the character well. And I also like as much realism as possible. The 2 companies are pretty even for representation of non-human characters and I think Sideshow gives me what I want better in human sculpts and paint apps. So Sideshow wins that one...barely.
Intricacy of sculpts on machines can't really be judged as Sideshow has not yet done anything like the Power Loader or the Terminators in 1:6 scale. But judging by the PF Grievous and Anakin's mechanical arm. I think they would do just fine. Hot Toys edges out Sideshow in that aspect just for having proven themselves already. But they only edge out Sideshow because Sideshow MAY do just as well...we don't know.
Costumes are pretty even between each company. I have to give Sideshow a slight edge because both companies give enough detail to things like functioning pockets and scaled zippers. But the Sideshow costumes just seem to be a little sturdier to me.
And another VERY Important aspect to me is accessories. Both companies pay enough attention to detail to give us functioning pouches and packs. Sideshow gave us the great detail and functional folding stock on the Stormtrooper blaster. But Hot Toys wins out because they tend to have even more accessories, and more functionality to the small pieces like removeable magazines for the Aliens pulse rifles. And with everything else being so close, but tipping Sideshow's way, this aspect pulls Hot Toys to the top...barely.
I think Sideshow wins Hands-down in the packaging department. But I also don't give a monkey's nut about how pretty the packaging is. That figures into the cost of the figure as well, and I would certainly prefer more accessories to a pretty box. But still, Sideshow DOES have the best box for every aspect of the packaging purpose. You also have to add in that they include outer shipping packaging designed to protect the box. THE FREAKIN' PACKAGING HAS PROTECTIVE PACKAGING (I am laughing as I type that). But even though I don't care how great the packaging is...I still want the packaging to be in good shape.
Edit 1 - Actually, I am fine with Medicom's packaging. I don't even LIKE Hot Toy's because they have that reflective aspect to them that makes displaying them in a direct light a pain in the butt.
Edit 2 - Buddy Gus touched on something that I missed. Customer service. The way Sideshow is so good with customer service adds to the price of the figure as well. How many broken Hot Toys pieces has anyone been able to easily replace? - I may have to switch my opinion to Sideshow winning...barely.
Edit 3 - Oh, yeah...and I want all of my 1:6 scale to match without having to re-buy every one of them...AGAIN! No clear winner yet, but Sideshow just pulled a little farther ahead...and it is the last lap of the race.