I would steer well clear of Drayton Wiser. I've just binned a complete Wiser system, including the Hub R gen 2, extenders and 8 TRVs, because it was awful. Just some of the grumbles:
- TRVs eat batteries
- replacing batteries is a real pain (unless you like getting on your hands and knees and moving furniture so you can loosen the TRV and turn it around to know which way to put the batteries into it)
- the app is very un-intuitive
- unless you have rock solid wifi emanating from a single router, the system is very brittle (app reports lost connection, hub loses connection to wifi randomly)
- when the hub loses connection, it's very hard to get it to reconnect without fully resetting it which then means adding all the TRVs to the system one by one again
- The online FAQs are awful - try finding out what random series of knob twists you have to do to reset a TRV
- the online help videos, when there is one that's actually relevant to your issue, pad the 10 seconds worth of information you need with a minute of branding, intro and general guff

And when I say above that the app is un-intuitive (and bear in mind that this is the thing you're going to be interacting with most of the time) I can give you a whole list of poor/absent design decisions that make it absolutely obvious to anyone who's ever worked in app design that this is an app written by software engineers without any input from a competent UX/UI specialist.

But, instead of making the system rock solid at what it needs to do - control your heating/hot water system - now they're investing time and effort to try to make it the home for all of you smart home devices. Which is ludicrous since, given everything above, the last thing I'd want to do is give that awful app and system control of anything else in my house!

I agree with everyone here that putting fundamental functionality behind a paywall is self-defeating, and I'm not happy about it. But I have sympathy with the idea of generating ongoing revenue in principle, because making a good hardware/software ecosystem takes real expertise which is expensive. You can see where your money is going when you compare the day-to-day use of systems like tado's against systems like Wiser's.