I previously bought the smaller bottle of this when I wanted to make sure that it was worth having a lot on hand--it definitely was, so the bigger bottle is great to have. Because while I appreciate the convenience of having the smaller bottle to toss into my bag, you can't beat having the bigger bottle around--if only so you don't feel like you have to save it up.
You should note that this is NOT a lube--you only need to use a couple of drops of it to work and I almost hate to think what would happen if you glopped it on like it was a normal lube. For me, I really love that this is a sensation liquid and not a true lubricant. All I wanted was the warming, not the extra lubrication--but if you were looking for a warming lube, you might want to look elsewhere. I did notice that as the warming action started, I naturally got wetter, though, so you might not need it. I don't think that that was necessarily because it was such a turn on, so much as it definitely increases blood flow.
The sensation does depend on how much you use, but I found that three or four drops was plenty to get a nice warming sensation. It does take a couple of moments to get working, so you might want to wait before you decide to add more. It feels very much like getting very turned on without needing to get turned on, you know? The heat really mimics the way you feel after a bout of foreplay.
What I found really pleasantly surprising was how nice it tastes. While it's not marketed as being flavoured, it does have a sweetly cinnamon-y taste to it. Too much will kill you with the aspartame flavor, but if you use just a few drops, it is actually quite fun to lick. Considering the effect blowing has on the heat, it has definite oral sex possibilities.
You do only need to use a few drops of this, so if you only want to use it on the more delicate body parts, the smaller bottle is enough, but I've found that the warming sensation feels great on other parts, like the breasts, neck, or small of the back, so if you are more exploratory, you might find you like having more to play with.