The eccos looks more complicated to use to me. It has a built-in looper and particular delay sound. The D1 has more delays and looks a lot easier to use. For that reason I would choose the D1 over the Keeley.
The Walrus looks like a nice Multi Delay and the Eccos just nails some particular sounds amazingly well. If delay is an important effect I’d use the Eccos alongside other options too if possible.
The Echosystem is a killer Multi Delay too and has some really unique sounds available!
I bought the ECCOS as it was a great price (25% off) and I only want the one type of delay, and the looper is bonus so I can take the Ditto off my board. It’s also analog dry through which is important when I run a wet/dry rig eliminating any unwanted latency. The WA looks and sounds good too, but having too many delay types causes option paralysis for me sometimes.