I have a Helix Depth and it works pretty much as advertised. It has a nice big face and a good backlight.
My major complaint is that the wristband is way too short to fit over a wetsuit. I don't understand how they could have designed a dive watch with such a short band. I bought a Waterborne band for it, but it looks ridiculous.
Be aware also that the watch is very large. I was a little stunned when I took it out of the box. This is what makes it look so silly with a replacement band.
On the whole, it does what it says it will do, but for just a little bit more, you could get a basic dive computer.