We went with Grohe--no complaints; great product

I have a GroheTemp as well. Works great, looks good, installation was pretty easy.

I have a Grohe and I'm happy. I wish the price was better.

Grohe user here also.
Very pleased.

I do not know if I understand exactly what thermostatic control does?? It is expensive in addition to a normal hot and cold water supply controls.

It's quite common in upscale European hotels. Essentially it's a knob with a calibrated temperature in degrees. You set the temperature you want and it holds it with reasonable precision (at least until the hot water runs out). It's a step above your average pressure balanced shower valve.

Found great price (same price or less than a plumber would pay wholesale) for Grohe thermostatic valve.

Here is a link that might be useful: Quality Bath

Dornbracht

Cost, IIRC, about $1500.

The plumbing gods were not slow to punish our hubris.

Two issues developed.

It has 2 small integral check valves. Grit was keeping them open causing hot to flow into the cold. Never could get cold water in the master bathroom sink in normal conditions for a year until we fixed this recently. Had to let the cold run for about 25 seconds in the kitchen as well. Since this fixture is so rare, contractor did not install tile to allow proper access to valves, so he had to hack away at tile beneath escutcheon.

The main cartridge needed to be replaced. The problem was that if all 3 shower heads were on, or the valves were opened too suddenly, or the water was turned toward cold, the water would become freezing cold and had to be turned off and on again. This is a $500 part, but was covered under the 4 year warranty.

These problems are tricky to track down. A licensed plumber refused to help him with this (we did not know how the hot was getting into the cold, and his experience told him how frustrating that could be to pin down), so my contractor trouble shot it himself, consulting with me several times.

Nothing looks better. And now that it works properly it's a joy to have. But beware the high end, and doubly beware the ultra high end.

The GROHETemps warn you to flush the thing well before using and they have small finger screens in them ahead of the control itself. You can easily clean these, you pop off the face plate and remove them with a hex wrench. If you were smart, you kept the little spouts they gave you with the unit to direct the water flow out away from the wall.

We Recently instlled the Grohe also, combined with the bar/showerhead kit. Water temperature always just right. However, water pressure is low. It is not enough to activate the pulsating setting on the showerhead. The 60-year old showerhead and 2-handle valves that we replaced had plenty of pressure and even got a good massage from a Waterpik type showerhead massager. Supply pipes are the same (1/2 inch).

Is there any setting on the valve I can adjust?