Taste and strength are not typically directly tied to the mg level of the liquid. I've never ordered from V4L, so I can't speak to how they hit versus other brands.
Unfortunately, since taste is such a subjective thing, there's no real way to gauge how "good" a particular brand is until you try it yourself. One of the things that helps is to search for brands / flavors you like in posts and see if the people who like them recommend something else. If the taste in what you have isn't pushing your buttons, run down to a local pharmacy and pick up some Lorann's flavorings. Search the forums for threads on mixing to see how to experiment with that. At least that way, what you put into the V4L juice isn't a loss, plus you might discover a new favorite flavor.
Strength is also somewhat subjective. The mg level tells you how much nicotine is in the liquid, but nothing about how it actually feels when you vape it. Some formulas, although they deliver more nicotine, aren't "harsh" enough to feel like the cigarette smoke you are replacing. For veteran vapers, thats a good thing. They want volume of vapor, but are now used to not feeling the scratchy throat feel that comes with cigarette smoke. For new vapers, they miss the feel of an analog. Because of this, some of the higher "quality" juices (preferred by the vets) are disappointing to the new users. You may be able to adjust the feel of the liquid by cutting it with more PG (less vapor, harsher), which will also drop the mg level, but it may provide the throat hit you are looking for. (Feel free to flame me, anyone, I'm out of my league on this point)
Also note that a lot of vets have switched to higher voltage "mods" in order to produce more vapor volume. Because of that, a harsher vapor would be overwhelming (and would tend to overwhelm the flavor as well.)
Hope this is at least a little helpful.
