First of all, I have spent around 1.5 - 2k with Mark Johnson and he's been very prompt and helpful and I've always received everything quickly - even my cupholder. I've had nothing but good experiences with him.
With that said, I think it's sad that so many of you are willing to say, "I've had a great experience(s) with him so you must just be whining or lying" and making excuses for Mark.
There was another NSX vendor that flat out ripped people off - he's no longer in business - but the sad thing was that so many people defending him and praised him every time anyone posted a complaint about him. I personally never had been experiences with this vendor either but many others did including some prominent people in the NSXCA.
Unfortunately, the people who had bad experiences NEVER posted anything about their negative experiences. That clearly didn't help the new people that went to this vendor based on the positive feedback posted on NSX Prime. An open discussion like this one may have saved a few people from getting ripped off.
I, for one, think this type of open and honest discussions is helpful to the NSX community.