Hi Brian... I did buy the Nimar housing, however, I haven't get it yet..I'm hoping to get it this week, as soon as I get it I will let you know my first impression. There is no much info about the new Pro line out there yet, since its a new product.
Ran from Mosaik Underwater Housings helped me with the decision process. He tested one of the new Pro housings, the one for the Nikon D500 , and he published a review of it. He visited the Nimar factory in Italy and he said the product its of a great quality and he has high expectations from it.
Due to a limited budget I had to decide whether to buy the Ikelite or Nimar housings, better ergonomics, better port locking system and back door locking mechanism combined with a tougher material (delrin), various port mounting rings and few other details made me choose the Nimar housing. However, this is obviously a leap of faith since this product its very new and there is no reviews from other users so far.( Fingers crossed)
I have no previous experience with the Ikelite system and by no means I'm stating that the Nimar housing is better. I read lots of good reviews about Ikelite and there is an ocean of happy users out there. I just simply made my decision based on what in my opinion will work best for me.
I'm not sure if you already own a camera, but if you don't, I believe a cropped sensor camera will serve you best for super macro as per many experienced photographers in this site.
Have a great day!