Good morning. PT, I have bought unflavored nic from heartland vapes, RTS vapes, and my freedom smokes. All of them were fine. I would definitely recommend getting the ry4 double. In my opinion, it's the best ry4 flavor. I used to mix it at 12-14 percent and it was ok by itself. Here's a variation on ry4 that is really good. I think it was called a Tribeca clone but I've never tried Tribeca. It is really good though.
13% ry4 double
3% graham cracker
2% acetyl pyrazine
3% ethyl maltol( cotton candy TFA)