My vote goes to Sensibo. I had a Broadlink RM4 and it worked okish.
Got a good deal on a Sensibo a few years back and it's been fantastic.
One of the best things about it is that it picks up the signal from the Heat Pump remote, so will sync it's state if you use the OEM remote (eg. someone grabs the remote and turns on the heatpump, the Sensibo app will detect this has happened and will show the heatpump in it's correct state, so you can turn it off using the App or the remote and vice-versa).
Works really well with Amazon Echo too.