Like zam said, if someone is very skepitical, do the experiments.
That's exactly how MVP won me over. Let me preface by saying, I am not on their test team. I do not get free discs, but I buy a lot of discs every month. A LOT!
In early 2013, I bought a handful of Anodes and Ions to experiment with, and they didn't work for me. I continued to be curious about them as I worked on my form and game overall, so I bought the whole line in Neutron this past fall and decided to just take an all MVP bag out to the course and work with them without having any other options. I decided to make a project out of it - an experiment like Zam mentioned.
I learned a TON about these discs in that first round and continued to do so through subsequent rounds with them. I felt like I could judge those discs on their own merits by doing this by only having the MVP discs to choose from and not reaching for another. I could always go grab those discs and throw a round whenever I wanted.
As others have mentioned, there's a characteristic to the flight of each disc that I noticed. While every mold doesn't work for me, and still doesn't, I'll continue to evaluate their discs just as I do of several other manufacturers and molds as I pick them up. I realize others might not be able to do this, but, what I've found is that my bag has gotten, and continues to be more MVP that any other manufacturer in every slot - putters, mids, drivers. There's a consistency, reliability, quality and sheer enjoyment I get out of throwing their discs.
And, honestly, before switching over to their discs I always felt like entering a tourney would be pointless for me since I didn't have the confidence. But, a few weeks back, I felt confident that I wouldn't get totally smoked and wanted know what the experience of playing in a local one was like, so I signed up. Wouldn't you know, I won my division, so that was cool as hell. I know for a fact the reliability of the MVP discs helped that happen.
I will say, mids are the tricky spot with me with their line, but I still enjoy testing them and look at it as a personal challenge to figure them out since I'm convinced it's likely a form thing for me. There's plenty of proof online that these discs fly just fine.
Being perfectly honest, at one point, I wrote MVP off after my experimentation with their putters in early 2013. But, I like what they are doing... their plastics, molds, stamps, lines, etc.... so I continued to be curious. Knowing my form and ability had come a long way since that first go-round, I gave them another shot. And, I'm glad I did.
So, take that for what it's worth. Everyone's results will vary, but that's my testimonial as to how I became a fan and user of their stuff. That being said, I still buy and evaluate other discs out of curiosity and for comparison. I buy a ton of MVP discs as well (expect my 3rd DN delivery this month today) and will be buying lots of Axiom discs as well.
I would expect that several others who are curious about flight patterns in new/existing molds would do the same. I would encourage you to do so just based on my experience. Even if it's not buying them, ask a friend to let you throw a mold you're curious about. I think that just comes with being a fan of the sport and the enjoyment in throwing discs in general.
You never know until you try... and try try again... yadda yadda yadda... ;-)