I have had a Z-wave system for close to a decade, been on Homeseer for 4 or 5 years now. I don't really use my Harmony with my lights in my setup, though.
But I bought a Caseta hub just for the sole purpose of their Pico remotes. I do have a Pico remote in my theater that I use to control my lighting. It just sits on the table on it's little pedestal. It's simpler/cleaner than using the Harmony. I have the Harmony Ultimate in the theater, and it's a little cludgy with lights. I have an Elite in my living room, but not lighting control on it either.
My theater lights are actually LIFX bulbs, controlled thru Homeseer via my Caseta remote. The Harmony can also natively control LIFX, but I don't want that. Confused yet? I like smart bulbs for certain things, but a theater with 11 fixtures is not one. I only have 2.
I am pretty sure that you can integrate Caseta wit Harmony straight up. Using a Caseta switch for each of your circuits. I haven't actually tried this though. I am impressed with their hardware, but I don't like configuring things on phone apps, but that's just me
Also, at one time Harmony had a z-wave hub you could buy. I wouldn't like that for whole home automation, but if this was your only home automation desire, it might be the simplest? I almost bought it several times, but never did pull the trigger.
Just be careful with the home automation thing. My wife wanted a way to turn off the bedroom lights from her nightstand. It could have been a simple RF controller for $25 and I'd have been done. Now I have a server rack with a dedicated computer for automation, and have spent thousands of dollars over the years. It's a fun hobby, for me at least