Today I got the two Solarforce hosts I had ordered a couple of weeks ago, after asking for advice here.
First, I ordered a black Solarforce L2 with an extension tube from lightake.com. It was only $10.82 which was suspiciously low. After I ordered it, it was pointed out that it was certainly fake because it could tailstand and Solarforce lights don't do that except with a special tailcap that you can buy separately. Although Daniel from lightake had assured me that the Solarforce L2 is genuine (he actually said it was "ture"), this light is definitely more similar to the Solarforce knockoff Ultrafire WF-504B that I have.
Second, I ordered a genuine gunmetal gray Solarforce L2 on eBay from ITC_shop. It wasn't much more, only $11.05. While similar looking, the Solarforce is definitely better quality. It has big o-rings in the head and tail whereas the Solarfarce has a big one in the head, but a skinny, pretty ineffective one in the tail.
Here are the three lights: Solarfarce L2 (black, top), Solarforce L2 (gunmetal gray, middle), and Ultrafire WF-504B (silver, bottom):
Knurling: The knurling on the Solarforce is more prominent with each diamond coming to a point like on a rasp. Each diamond on the Solarfarce is flat. The Solarforce knurling is better, but I think I prefer the Solarfarce.Maybe the Solarforce would be better if you were wearing gloves. You may have to click on the picture below to see the difference, with the Solarforce on the left and the imitation on the right.
Tailstanding: The Solarfarce, as already mentioned, tailstands. I don't need a light to tailstand that often and it probably makes the button harder to push, especially with gloves, but I think I prefer the tailstanding cap. Both clickies are about the same, the Solarforce might be a little better and seems better on half-presses to change modes. Although the genuine Solarforce clicky protrudes, I don't think it would be that easy to turn it on accidentally.
Lanyard: I don't like lanyards that much, but I'd rather be able to have one than not. The lanyard included with the Solarfarce feels kind of cheap. I like the one that came with my 504B better which has more texture to it.You have to buy a Solarforce ring separately if you want to attach a lanyard to it.
Anodizing: The anodizing of the Solarforce is a little more of an olive color than "gunmetal" which I would think would tends towards a bluish gray. It is pretty much perfect though. I was told one way you can tell a true Solarforce is to run your thumbnail down the side of a smooth part like the head and you will feel tiny little ridges, which holds true. The bezel is anodized all around and screws in very smoothly. The tail end of the body tube has some kind of rough anodizing, but it's not visible when the light is screwed together. The Solarfarce has shiny black paint (maybe anodizing) on the body tube, but the tail has more of a matte finish. The head is somewhere in between those. The picture of all 3 lights together shows the difference between the body tube and tail. It's not that big a deal, but it should be more consistent.
Conclusion: The Solarforce definitely deserves the praise it gets. It is well made in just about every way. I don't necessarily like all the choices they made, but for the price on eBay, it was well worth the money. To really make it perfect, I would still need to get a flat bezel ($5.76) and a clip ($5.01) which would about double the price of the host.