[jzawodn]

Yeah, I used virtually all Z-Wave switches and dimmers in our new house (and motion sensors, temp sensors, etc) and haven't had an issue. The one time things seemed a bit laggy I had to "optimize" the network, which I realized I had NEVER done until that point. All issues went away.

We have well over 100 Z-Wave devices spread over 4000 sqft.

[X-Istence]

That's less devices over a larger area than I had.

My house was 1200 sq ft, with a little over 200 devices.

[kansface]

What does optimize mean in this case?

[AdamJacobMuller]

The Z-Wave network, while being a mesh network, is not a dynamic mesh. Nodes follow a precomputed path from themselves to the controller (with backup paths -- it's based on a node having a predefined list of adjacencies). You need to regularly poll each node in the system and determine it's optimal path from controller->node and node->controller and redefine it's adjacency list.

This process is entirely automated but does take some time. It's absolutely critical to do this when adding a new device (both for the new device, as well as the overall network) but I found that just doing it regularly works great. I have all my networks configured to do this at 4AM daily since the network is unusable for the few minutes it takes.