Ive tried several "vape shop" tobacco flavors and most were pretty terrible to say the least. The ones that actually tasted like anything tasted like a cigarette smells NOT like they taste when you actually smoke one. Is this the flavor you guys mix or are you mixing flavors that actually resemble smoking a cigarette not sniffing an unlit one?
It's probably pretty close to impossible to get a vape to taste exactly like a burning cigarette, for a very good reason: nothing is burning. Burning actually gives a very bitter taste, and by the time one is enough of a vaper to start making DIY juice, most want nothing to do with that sort of burnt bitter taste.
The Virginia (high-PG) ejuice I got from MyFreedomSmokes was *similar* to the taste of Virginia Slims; at least, close enough to be a good substitute for me. But really not *the same* which kinda messed with me when I had 4 days of no vaping during my extreme illness following my appendectomy last summer.
Tobacco Express "Virginia" flavoring is very close to that taste.
One flavoring I'm playing with lately is Inawera's "Coffee Tobacco"; it really nails both flavors, even the scent, it's not sweet at all, in fact it's rather bitter like both coffee and tobacco, but it's a different sort of taste entirely, from that Virginia I used to like; a "rounder" scent, more like pipe tobacco.
But for the most part, what you said is true: tobacco vapes taste more like an unlit cigarette smells -- I used to run my unlit cigarettes under my nose for quite a while before lighting them, that scent was so intriguing. You'll find that the longer you are away from actual cigarette smoke, the more you'll be glad that vaping tastes nothing like that.

In the meantime, for DIYing tobacco vapes, there's a flavor additive that can be used, to give a more "authentic" (less sweet) taste, called Bitter Wizard -- I used it with that Tobacco Express "Virginia," and it helped a great deal. One or 2 drops at most, is all you need, and it really eliminates that sweet whang that most tobacco flavors carry.
Andria