A couple of years ago, a housing dealer asked me what kind of housing I was considering purchasing for my Nikon D850. When I responded that I was thinking about buying an Ikelite, he growled, "Why would anyone put a D850 in an Ikelite housing?"
I responded, "To keep my camera dry." For what it's worth, I use Nauticam, Sea & Sea, and Subal housings in addition to an Ikelite. All do a great job if I do not manage to screw things up.
I have used an Ikelite housing for my Nikon D7100/D7200 cameras for around ten years. The housing was sent in for service work and an electronics upgrade back in 2017. Unfortunately, a user error a few weeks ago resulted in a flood that destroyed my D7200 camera, favorite lens, and housing electronics package. Again, the flood was the result of an error on my part and not because any issues with the housing design. Given the circumstances surrounding my flood event, the same thing could have happened with any of the housings I use.
The flooded housing was returned to Ikelite a couple of weeks ago for service/repair work. Just today, Ikelite notified me that my serviced/repaired housing was being shipped back to me. When I have sent Ikelite equipment in for service work, the service department has always taken very good care of me.
Now, when I get my housing back, I will be adding a vacuum valve system to it. I like the Vivid Leak Sentinel that I use on a Nauticam housing and I'll be shopping for one to fit the Ikelite. Hopefully, the addition of the vacuum valve will help me avoid future mistakes when distractions are present. A vacuum valve system is cheap insurance.
When you consider housing choices, it is worth factoring in what kind of strobes you intend to use and how you plan to trigger your strobes. An Ikelite paired with a D850 usually requires the use of a sync cable rather than fiber optic cords. Of course, manufacturers have electronics packages that will convert the sync signal from your D850 into a signal for fiber optics. The downside of these electronics packages is additional cost. My sync cables have always done a really good job.
Another consideration is dome port selection. Can you get the size and quality dome ports that you want to use? This said, the last time I looked, there were options for large, mineral glass dome ports available for Ikelite.
I still have not housed my D850. One of these days, I need to.
The short story is that Ikelite makes quality gear and provides exceptional service support!