We want wired since our concrete block walls block signals fairly well, and the location is easy for both external sensor and vrc720. We have a small area of ufh in the extension but I suspect that it doesn’t justify an additional controller.

One thing that has caught us out slightly on my (recent/ongoing) install is that you have to choose either all wireless or all wired configuration for the sensoCOMFORT units. No mixing and matching. 

We're having two sensoCOMFORT units 1 to regulate a section of UFH in an open plan area in the downstairs of our house and 1 for the rad circuit (calculations were marginal on whether we'd run the rads down at the upper limit of the UFH flow allowance of 45C - so safer to separate in our scenario). 

For us one of the units was going to be located where the previous UFH thermostat was so would be easy to have wired, but wanted the rad circuit to be a wireless controller as no idea where best for it (or if we'll even have it reacting to room temperature etc). Turns out this can't be done, so we're waiting on a fully wireless kit to arrive. 

Impact of the wireless option is the outside temperature sensor is then wireless (so may need its batteries replacing in the future). Pros and Cons. But worth having a think about given the outdoor sensor needs to be >2.5m above ground level on a N or NW wall. 

I would have liked to have had at least 1 wired stat as then I wouldn't need to ask the question - what if the batteries die while on holiday? ... 

This is a perfectly good reason since I’ve read the Vaillant controls are not intuitive. I’ve found data sheets for both and will plough through them. But what is everyone’s experience?

I’ve spotted the sensoCOMFORT also has a title of VRC720/3. Is it simply a more recent issue?