Zoos - I'm a power vaper and 24mg is about as strong as I can go without being loopy all day (ok, or I'm a whimp

) but I did notice that the stronger, first mix that was more like Smooth8 with the 24mg did have some bite to it in the TH area.
I would say that whatever you like from Halo mg wise you should go with that for the nic base and believe me when I say you won't have to worry about the concentrate drops lowering the strength as they are really powerful flavor wise. You could also go with the 36mg and some extra PG/VG in case you do find you need to cut it down a bit. Just mix up the cut base first and then add the drops.
Buster - I remember some of those "just like" posts as well but again, TW's price was up near the $1/ml range and I was looking for at least 1/2 that price. Once TW put out the concentrates I was sold and I think this could be a huge growth area for them and anyone else that sells the same thing.