WW is working great for me. Since I finally got Home Assistant running five months ago, I am currently using a combination of WW and HA to run my kit. Over time I am improving my HA rules, so am using WW less and less. It's a great backup though, and I have it working in harmony with HA.
Back in October I paid for a year's subs to WW. I don't regret that in any way. Would I renew my subs this October? I'll have to make that decision nearer the time as it will depend on how much I've improved my HA rules.
My HA rules are currently quite clunky, and I haven't worked out how to validate that a command has got through to the inverter, so I run any important rules several times to allow for inverter dropouts.