These are all great headphones in their own right, I don't think there is a single member here that will have a word otherwise. With that said, although each may do something gerat and even better than the Pimes, when you consider the overall package none of them is of the Primes' caliber. I don't want to go into details, only will mention that Primes have superior clarity, detail and are the most neutral from this group. Also the least fatiguing to listen to and that is very, very important. Specifically in regards to TH900, they have notable V-shape frequency response and exaggerated lows that I will even describe as boomy. Yes, they are fun to listen to but so are countless other headphones and that is not enough. For many people that is enough, for me the Primes are technically superior and outshine them in almost every aspect.
As for MrSpeakers being a small company - this is the most ridiculous argument I've heard in a very long time. Really? And so were Apple, and Google, and Facebook, weren't they! Big corporations cannot innovate, hence the reason they acquire small and nimble innovators, but let me stop myself as I start to drift away here...
I'll tell you this (and I assume your Primes are new): make sure to burn them for good 100 hours before you engage in more or less critical listening. Alternatively, burn them while you listen to them and just keep open mind that they will be improving their sound. After that, take them to a better audio shop or someone you know with a top of the line headphones, and compare them. Then we'll love to hear back from you how it all went (even if we already have a good feel how it will go