Walt,
The NGT-9000 is $6,000, and that's the sales price that ends soon. It appears the normal price is about $800 more. I think you have to add a $500 GPS antenna and install kit to that after the sale is over, right? The Appareo at $3,500 with the antenna, plus a $900 stratus doesn't get you anywhere near that. So I did assume we were looking at the UAT units because the price of the 9000.
I'm not a deep expert on Appareo either, but as you found on the website it says "Appareo is an accredited FAA Parts Manufacturing facility" which you can't be until you've made at least one approved part, so it's clear the transponder is not their first product. Also, given their success at Stratus over the last 3 years, it's hard to call them a newcomer with no experience. Just trying to keep the data accurate when someone says this is their first "go at it".
Again, both good products, but I still believe they are targeted at different use cases, and someone looking to become ADS-B compliant should look at all the products out there.
--Ian