I'd been using Ikelite Housing sine about 1996-1997. Current one is my 5th Ikelite Housing (Olympus EM5III/OM System OM5).
First one in 1996, I bought a 2nd hand Canon AE-1 (Film camera that I had at that time) housing off the internet and got it shipped from USA to Thailand. Which I found out that there's a leak due to corrosion at the strobe connection point. I'd e-mail Ikelite, got the reply, send just the backplate to USA. Ikelite replace the whole new back plate for me and charged me only shipping cost.
Later, when it come to Digital Camera, I'd used Olympus C-7070, Canon G16, Canon S95, all in Ikelite Housing. I got Ikelite DS-125 Strobe when I bought the Oly C-7070 and been using it as Single strobe with hard-wired TTL since.
When I got the Canon G16, Ikelite released DS-161 and had an 'upgrade' offer to convert their old DS-125 to DS-161, which I did. Unfortunately, Canon G16 in manual mode will not send TTL signal out - this is Canon design. So I'd been either using the stobe in manual, or TTL when I use Aperture priority.
The Housing for Canon S95 was actually for my wife, which she still use. as the camera has no hotshoe, so it's fiberoptic only. I got her Inon strobe, S200 may be, which got flooded in about 2 years. (I got Inon strobe for her as others in our dive group use this model, so she can get consultation from others.)
About 2 years go, the Canon G16 is dying out, screen starting to blacked out, button sticking, etc. So I decided to change camera to Olympus EM5III. It's older model but with the release of OM System OM-5, I would be able to get replacement body - they're physically the same. And I got Ikelite Housing for Olympus EM5III and TTL dongle. DS-161, even after 9-10 years, of not heavy use, were still working fine. The battery starting to show its age - lost charge when stored for over 3 months, taking long time to initial chage after storage - but once it's fully charged, it work.
Last year, I got 2nd strobe, DS-162 and dual Sync cord, it's the one with Video light. (I don't think they show this on the website anymore. - only the DS-232.) I still shoot all Photo with Camera in Manual Mode and both strobes set to TTL.
There's some frustration when set up as I think my camera hotshoe probably had some worn-out spot for the TTL connection. But once I got it properly aligned, there was no issue. I just came back from a 3 night liveabord trip where I only had setup the hotshoe properly once and leave it there - it worked for the whole trip.
In the recent week, Ikelite just announce a couple of New Strobes. This time, they go fiberoptic. Check out the links below. Currently they said the Fiberoptic TTL on these new strobe are compatible with Canon (with their TTL Fiberoptic Additional part), Olympus, Panasonic. Nikon and Sony compatibility will follow soon - that's what they said.
Big strobe - Ikelite RC-165
Small Strobe - Ecko