Down here in Australia the price difference between Nauticam & Marelux isn't that great unfortunately - tariffs might be the cause of the bigger price difference in the U.S. Nauticam is supported extremely well by their distributor here - good stocks of housings, ports, focus & zoom rings, etc. Isotta fairly close to that, unfortunately the distributors for Seacam, Aquatica, Marelux, etc keep little stock and don't keep their websites up to date when new models are released etc. Having said that I am considering the Marelux Apollo III 3.0 - they have some features that suit me. The local distributors are still listing the 2.0 and haven't even listed the 2.1 yet so I will have to email them about a price for the 3.0. They haven't listed the housing for the A7RVI yet either. The other distributor doesn't list any of the Marelux strobes. I will take a look at those UWPmag articles that you mentioned - cheers!