Taken from Mr Nice forums.
I write this not as an expert on G13, but as someone who was extremely interested in this variety due to is origins and legendary potency. I made it my business to understand who had some legitimate G13, and who had some mystery varietys labeled G13 but could offer nothing of substance to back up their claims of having such a variety. From what I understand, you can acquire hybrids legitimately related to the G13 from Sensi Seeds(G13xHashplant), Soma Seeds(G13xHaze male) and Mr. Nice seeds(G13xSkunk#1, G13xWidow). From reading the forums for years, it is generally agreed upon that the Sensi Seeds G13xHashplant aka Mr.Nice has lost some of its guster in recent years. Somas G13xHaze male is said to have been found in a small handful of seeds given to him by Ed Rosenthal which were in turn gifted to Ed by Neville(as I understand the story to be). This was a Haze dominant G13 hybrid, but non the less it has some legitimate claim in my eyes if the story is true. And there is the Mr. Nice G13 hybrids, which are infact worked on by Shantibaba and Neville here at the Mr. Nice camp. I dont think anything else needs to be said about this revelation.
Now as someone who wanted to put his money into the sure bet that what I was getting was G13, I did alot of research before looking to purchase the variety. Anytime you are looking to purchase a variety, you should do research first. I pretty much arrived to the conclusions I am stating here in this thread years ago, as it was clear where my best shot was at obtaining legitimate G13. Decyphering all of the propaganda out there on the net can be hard, there are alot of people who claim to have something but yet rely on nothing more then hearsay as evidence to their varietys supposid origin. As someone spending some money on a variety, hearsay isnt good enough for me. I want to know who has what, where they got it and if its worth the money they are asking for it. That to me is a perfectly logical line of thinking when considering a purchase on anything in reality.
There are varietys such as the LG13 and the Airbourne G13 which are said to be the real deal G13 cuts. But neither of these varietys can be authenticated as being legitimate, and in particular the LG13 bares little to no resemblence to the original G13 hyrbids. While the Airbourne G13 is said to be the G13xNorthern Lights hybrid Neville released years ago, again there is no solid evidence other then visual inspection to authenticate these claims. And there are folks who have varietys they call G13, sometimes multiple unrelated varietys they have labled G13 which infact are not related to the original G13 what so ever. Its just a name they picked, to identify an above average specimen. This is the case of Pacific G13, which I discussed at length with her privately and the information presented above were the results of my inquiry. There is also the Socal G13
Quote:
Another semi-known G-13 is the SoCal G-13, which is said by a few to be better than the pacific/airbourne cuts, but the SoCal G-13 is a highly guarded clone kept in small circles supposedly, and you probably wont see it on the market anytime soon - unless someone like sugenite do some crosses like with the pure kush and sell it for 1000. Good luck with that though.

which many claim to be the real deal as well, but yet have nothing to offer other then hearsay about the authenticity of these varietys. While they may infact be good, there is little evidence to support their lineage.
In conclusion there are alot of companies and individuals claiming to have something they do not. Some of these claims, while hearsay only are seen by those making them as true. While others are simply making stories up in an effort to sell a variety quicker, or in order to gain some type of fame or furtune by possessing something which is deemed rare and elusive. There are people who have something very special marijuana wise, but use the G13 monicur in an effort to promote their variety as something it is not. There are others who just want to take advantage of the legend of G13 to sell seeds quicker as well, it is up to you the consumer to decifer who has what and if it is worth spending the next 3-4 months of your life growing. But all of the varietys on the market that have legitimate status can be traced back to Nevilles G13