Do you have a Persei already? Otherwise, from what I saw shipping last, that combo will work, but I believe only the insert is guaranteed with the core - the stainless steel tube that has been shipping with it is a damned nice convenience that allows me to leave multiple setups ready to go AND my Persei seperate.
I don't think that piece is guaranteed to accompany it forever unless UPtech would consider endorsing that combo... A home/tailgating combo that rips hard, while leaving the Persei itself as the option to make it truly portable?
There's some marketing ploys with the availability of that tube (and the shorty insert that current comes with the small SS kit tube minus bottom as well).
I've currently got two coils in my SR-74, loaded about 3/4 gram total and has been going for a couple weeks using it for when I don't have something else available. Maybe a session a day, maybe more, and I'm always getting something after 10 secs if not sooner and I do believe my AW's may be growing a bit tired, seems much more consistent on the Core (which dialing DOWN, not UP seems to be the key to flavor, just might take a few secs longer to make the same size cloud since you can maintain the same temp window with a slower draw). This thing reminds me of the Bender a lot...
I've had mixed success using the older carts in this manner, but as I learn the SR-74, it really seems to have delivered... I just now need to figure out when it wants more, as once it's all melted into the coil there's no gas gauge (I've previously been leaving wads on the top of the coils which eventually melted down and I put more in then, which with backreading sounds like too much, but I've not had a drop leak into the bottom yet.... the screen? different story, but wary of pulling it until I calm down with the draws).
Big clouds haven't really seemed a necessary goal for me to achieve so far. I know they're there as I grow to appreciate the power driving the device, but I allow it only to get as far as I want without seemingly too much waste, but it gets me there much quicker than anything short of dabbing! If you want to get stupid with it, just be warned that the stupid will likely set in 7-10 minutes after you started being stupid