Yeah I actually did a relatively deep dive on researching their history. I learned that BC FORGED actually existed before Signature, and both source their wheels from the same factory in Taiwan. In fact, if you were to look at the designs they both offer, they're nearly identical with the exception of a tad of variance between them (eg SV104 and RZ21).
Signature is definitely much better in marketing as evidenced by their popularity here on TMC. But, like with any vendors on community forums, the perception that Signature dominates the market exists in a vacuum. If you were to search BC FORGED vs Signature, there exists other car enthusiast forums that BC seemingly dominates and has market share of, the same way Signature does here. But, no doubt Signature has a clear knack for marketing via social media.
That said, I mulled over my decision between BC and Signature for months, before I ultimately landed on BC. The main selling point for me was that there were several reputable online vendors that sell BC, whereas Signature seemingly prefers direct marketing sales. And, I had the option to finance it, which is always a plus. No doubt though that most people looking for forged wheels probably are not looking to finance it like I was.
Here are street view photos of my BC FORGED RZ21 in 19x9 +33/24 staggered offsets. They came in at a featherweight of 19.6lbs INCLUDING the valve stems and center caps. I got them from Danny
@MODEL+ for 3.4k SHIPPED, and they were delivered in literally three and a half weeks after I ordered them. I absolutely love them, and I'm happy to share this info so that people know there are other options for premium forged wheels other than Signature on these forums. More options and competition between vendors only benefits us as consumers.