I have Traveler, planted alongside Freedom, Osage and Ouachita, all upright thornless varieties. The Traveler has produced a few primocane berries, with a few more to come. The flavor was OK, not really sweet, and big seeds. Berry is about quarter sized. Still tastier than our wild BB’s.
My PAF has some blooms on it, so we ought to get our first berries from it soon. The last two varieties are floricanes, but that’s OK with me. All of them have got so big that they are no longer upright, they’ll be trellised soon. I wish I would have done that earlier, and tipped them, as I probably would’ve got a bunch more primocane berries.
The only other primocane blackberry I know of is PA45, but it’s thorny. @clarkinks planted a bunch of those last year, but I think they got hit hard by a severe winter.
Haven’t heard anything about Stark’s Black Gem, but I think it’s a U of Ark primocane variety. So, it ought to be pretty good.
As you can see on another thread, I have 5 Triple Crown plants that have really taken off. Yes, they are trailing, but I got them trellised. Next year we ought to have more berries than we can handle.