I love the idea of being able to control each room independently, but the thought of having to replace that number of batteries regularly (how long are you getting from them?) and the upfront cost of buying them (€600 for a small-ish house, maybe €1200 for a bigger house) would put me off.
I like the look of the Drayton Wiser stuff and may consider that system if support for my current Climote system ends. That said, I have TRVs on most rads but rarely have the need to adjust them. Downstairs is heated in the mornings on cold days or into the evening and upstairs only gets heat in the run up to bedtime. The only exception is the downstairs guest room where the TRV is upped if we have people staying.