I am the poster child for indecisiveness so I may not be the most helpful.
The first thing I would consider is why you feel unrest in this area. So you feel like it isn't working as well for your son as you would like? I know people say that if isn't working, don't fix it. But in general, do you feel like it is accomplishing what you are looking for. Also, just because VT looks better, it may or may not be the best fit for your ds. I have researched SO MANY MATH programs!!!! I think they all have their niche. Each is different and speaks to kids differently. I know that in school, all the kids are learning from the same math program. Yes, I do know that there will be a few kids who are left behind but in general, the teacher is what makes the difference in the classroom no matter what math book they use. With us homeschooler, we are all looking for the program to make the difference with the kids.
As I look to the future with my own kids, I have become less and less concerned with the "rigor" of the program and more and more concerned with whether or not my kids are growing from it and whether or not they are retaining it. I definitely consider it a bonus if they actually like it too
If your son likes MUS and is learning, then I would probably be hesitant to switch. So many times I also hear people bash a program at certain stages but like you said, there are people who rave about it too. Don't worry about what others think. If you like it, I would stick with it personally. And while I do think VT is a great program for some, it isn't for others. I have looked at it myself and had originally planned to use it because of so many wonderful reviews. However, as my kids have gotten a bit older I now feel it is not for me (many my oldest, she would be set to start in 1 year if I went that route). At first, I actually thought that is what I was going to do. But then I decided against it. I personally (totally a personal preference here) didn't like that they would learn all of algebra but then not see it again once they moved into geometry. I decided that I wanted my kids to have Algebra 1, then Geometry, then Algebra 2, and then Precal. I like that they will get review of the algebraic concepts in Algebra 2 and the geometry concepts when they study Trig (that may be in the Algebra 2 book but I can't remember). VT pushes that kids can finish this program quickly so that they can score well on the SAT and ACT test. I was concerned that they might forget some of the key math concepts on the test if they didn't have that extra review. And this may or may not be a problem. For me though, I am choosing review over doing all of the algebra at once and all of geometry at once. Again, this is a personal preference.
So, with all that being said, I would also not discount the fact that you have unrest. Maybe the spirit is leading you to choose something else. If so, I would just start praying about it. If the Lord is leading you to VT, I would definitely do it. But I would spend some time praying about why you have unrest and as God for clarity in this area.