Ughhhh I'm not that good at descriptions..... (well, getting them out of my brain into yours lol)...
Out of the 5-10 different OGs I smoked from Cali., the majority of them have a real similar profile, which may vary, but has those traits... kinda like the traits of sour diesel, but without the sour diesel funk.
I would say the OG18 reminds me of the better, stronger, more 'kushy' and less of the fruity watered down traits.
RP description of OG18 is to have a very, very "OG" strain, I think they did a good job.
I used to smoke on some sour d that was so amazing that I would love to smoke just that strain and never any others if I had the option. Was a real amazing pheno grown by a pro., the stuff that penny punchers will happily pay a premium on. The traits in that sour d that I associate with true OGs are the traits I like in the OG18.
I ordered their sour diesel, because their OG was so similar to my fav. Cali. OG, so I'm hoping their sour diesel is what I'm looking for!