I do not think that you will find a complete list that compares all features between all companies. The closest you might get would be an article that reviews chess clocks, and compares them. I will tell you how I picked my new clock, since it still involves finding the information you are seeking.
When I got back into chess in the last year, I bought a new digital clock since it was time, and I only had some nice old analog clocks. I went to the major manufacturers, DGT, VTEK, and Chronos, and their websites.
Virtually all chess clocks have these basic features today. Using a blitz game of 5-3 as an example, this is how they work:
- Fischer’s clock – The clock starts at 5:03, runs down to 5:01 and after the move ends up on 5:04.
- Bronstein’s clock – The clock starts at 5:03, runs down to 5:01 and returns to 5:03 after the move.
- Time delay – The clock is paused at 5:03 and nothing changes after the move.
For more on this, I pulled this from this nice article.
Beyond that, most of the features have nothing to do with chess. They are more along the lines of how many pre-programmed time settings are there, how many personalized time controls you can program in, what is the quality of the materials it is made of, brand reputation, and is it FIDE certified?
Those things, you just have to compare from clock to clock, and there are a lot of reviews out there comparing chess clocks to guide you. You can also look at the manuals to get an idea.
I, ultimately, went with a DGT3000 primarily because it is FIDE certified, and is the clock that you see at all the international events. You can look at the manual here, and see a lot more about the features.