I can't answer all the questions with an absolute, but here goes my opinion anyway…
First I have not tried MBV’s Butterscotch as I’m not a fan of that flavor. But from the thousands of threads I have read, I have never heard more people rave about Butterscotch than they have in this thread about MBV’s version. So with that said you hopefully will find this a great solution for the hunt.
As far as a peppery taste of the nicotine goes. I have had three experiences with this pepper phenomenon.
#1 My nicotine level was too high and once I reduced the nicotine, that nasty taste went away.
#2 I was using a new coil and a silica wick (atty) that was all gunked up

. How could that be? I did a dry burn on the coil and once I thought it was good and clean, I filled my tank back up. Good to go right? No I went

and really felt sick to my stomach. I discovered that the coil that the silica brand I was using was junk to say the least. Once I went to a different brand of wick the problem taste went away.
#3 Also I discovered that juices like to be vaped at different voltages/watts than other juices. This can be true even with different flavors from the same vendor. As I learned that, if I have/had a juice that doesn’t taste right I will adjust my voltage level (provided you have a vv/vw battery device). And the problem was resolved.
Now if your device is not variable just make sure you have as low a resistance of a coil as possible (generally 1.5 to maybe 2.0 ohms). But number three is not the most likely cause so you should be okay there.
And the last point is try different flavors types, even ones that you don’t think you would like (of course try ones that sound good at first). Many here in this thread have said how surprised they were when they would receive a sample of something that they would have never considered purchasing on their own. That they loved the juice and would end up reordering the flavor again.
Sorry for the reply in long format, but I felt chatty at this moment. And that doesn't happen often (you just got lucky

)