I'm contemplating in using Zelio PLC's for a lighting control project. Whats your personal experience with the far as reliability, longevity, support, etc...

I haven't come across Zelio yet. AB works well from my experience. Modicon is ok, but I'm not a huge fan of theirs..

A Zelio is a 'smart relay' more than it is a PLC.
I think smart relays are great for timer replacement.

First Zelio I installed was probably 15 years ago.

Use the free software for program development.