I think it makes quite a difference, but it's also amazing how much of a difference that difference can be.
I know ... that didn't make much sense, so allow me to explain ...
3.7 v 5v ... yes, there is a difference if you're using the same juice and the same atomizer. That will, however, change once you switch to a different brand of atomizer ... or a different resistance ... or a different juice ... or if you drip ... etc.
3.7 with a LR (low-resistance) atomizer will give you the high voltage experience; however, in my experience, the low resistance atomizers don't seem to last as long as regulars. Again, this experience changes if you're dripping into an LR atty or if you're using something like a LR cartomizer.
Unfortunately, there isn't any definitive answer on what will give you the best experience ... you'll just have to experiment a bit with different juices and different equipment.
In my opinion, for what it's worth, I think that clear juices (e.g. menthol) work just fine on normal resistance or 3.7v while darker juices (e.g. coffee flavor) work a bit better on lower resistance or higher voltage devices.