Good example of what is essentially a corollary of Murphy's Law: There ain't no such thing as a perfect machine. We complain....then we improvise
That's a good attitude. I have found that there's an art to reading product ratings/reviews. I might read one or two 5 stars, but then I go to the 3 star and lower to look for any common problems. There is always a chance of getting a lemon, but not as many as people claim. I think a lot of it is user error and also that usually you get more people complaining than praising.
If you have a problem with a product and go on a forum and see that some people have had good luck with it, then you should consider that perhaps you need to adjust the process.
Now, although I've had very good luck with the V-P, there is no doubt that it can be finicky. You
do have to get the right angle and move the primers around once or twice, but once you do they flow just fine. If primers flip sideways, then the tube must be a tad too big. Sideways, a primer should be too thick to slip through the opening if it's the right size. Flip upside down? Don't know how that happens, but I believe those who said so.
My one worry is that the V-P depends on tight fits and I can see those wearing.
Tip: if you predominately use one size primer, use a piece of tape to make a "gate" across the other one to prevent spillage.
Does anyone know the difference between the original and the new one that they say is improved?