I have been using Nicotine River since they showed up on ELR.
The flavoring is priced right, and I love the 60ml 'bullet' bottles, especially with the twist cap that also comes with them.
The VG may not be the cheapest [$$$] but the quality is super. It is palm derived, and really sweet. I was sure I read that NR palm VG was part of the Rain Forest sustainable farming Alliance, or Grant mentioned it, but I couldn't find it on the website, so I called them. After the call was over, 10 minutes later I get a call from Sam, their head chemist, and he explained it all to me. He even went to their supplier and got all the specifics before he called me. Their customer service is second to NONE, and has been also on the few times I had questions before. I know they are busy, but they always take the time for my little world.
I buy their nicotine in the 150ml bottles. Perfect size to use, perfect size/shape to fit in the freezer, and I can keep all but one factory sealed. The bottle has a foil seal on the 1.25" mouth. I still use a syringe for my nic, and I just poke a small hole in the foil and draw it out, and there is hardly any air that gets in the bottle. I can usually get 90% of the nic out before I need to open the foil more. Just keep using the same small hole.
I mix on a magnetic stirrer, and I add my nic last, and I don't use any heat, ever. The friction increases the mix from room temperature to about 105F when I shut it off. I have mixed many things with magnetics for 50 years, so mixing e-juice with it was just natural to me. I put the nic on top, and can watch it gently mix in, and since it (nic) is heat sensitive, this way it gently heats as it blends in. The first thing I noticed when I switched to NR nicotine is how easily it blends into the rest of the batch......not blotchy or swirly like the others I have used. Never harsh, always smooth, and with their VG it just works right together.