It depends. Sannie offers a couple different highly stabilized lines, like Sannie's Jack which is an F7 right now and should be extremely stable, or Herijuana which is an IBL, which is about as stable as a hybrid can get. Most reputable breeders will have at least one or two strains that they have worked to at least F4, which is where you start to see a good degree of uniformity. Of course, real landrace seed is generally going to be true-breeding, or at least produce a very, very slight amount of phenotype variation; but real landrace seed is harder and harder to find these days. Basically, just look around on a seedbank and see if you can find anything worked past F4, or even better to the point of true-breeding, like Bubblegum from Serious.