If I had the money I would get the control4 system. But they are really expensive. (As in $40,000 and up, plus maintenance fees.). So typically people looking at SmartThings are not also looking at control4.
Fixed Location Devices like Locks and Lightswitches can get tricky
As far as zigbee versus Z wave, you have more choices of Z wave devices in the low-cost do it yourself category primarily because of the Wi-Fi interference issue. This is particularly true for fixed location devices like light switches, locks, receptacles, and window covering controllers.
That’s because if you’re talking about a small battery-powered sensor, it’s easy to just move a couple of feet to the left to see if you get less interference with local Wi-Fi.
But if you’re talking about light switches or locks you’re kind of stuck with their location. Again if it’s a control4 type installation (they use a proprietary Zigbee) The installer has the tools and the expertise to deal with most interference issues. Since that hasn’t generally been true for DIY people in the low-end of the market, it’s just been easier for many people to go with zwave for those set ups. It doesn’t mean you have to, it’s just something to be aware of. Which in turn means more manufacturers making zwave devices for those purposes.
As far as changing the the channel, you can likely change the Wi-Fi channel if you own the router that is generating the Wi-Fi signal.
I have a problem at my house most weekday afternoons around 3:40. My SmartThings arrival sensor, which is Zigbee, will start losing connection to my network. My assumption is that one of my neighbors has boosted Wi-Fi and a kid who gets home from school around then. Unfortunately, the Zigbee channel for the SmartThings coordinator is randomly set at the factory and cannot be changed afterwards. So since I don’t own the Wi-Fi that’s causing the problem, it’s been very hard to find a solution.
Separately I had an issue where we ourselves had a Wi-Fi booster. If I put it on the west wall of one room, everything past that on my zigbee network lost connection to the SmartThings hub. If I just moved the Wi-Fi booster to the north wall, everything is fine. So sometimes it’s as small an issue as that.
You can likely be successful with either all zwave or all Zigbee or a mix. As I said, I do have a personal preference for zigbee but I will choose based on the specific device I want for a particular location. I originally chose a Z wave door lock, for example, because I knew I needed to boost the Wi-Fi in that area for some cameras and I just didn’t want to deal with interference issues.
There is potentially an argument to be made that zigbee may be more “future proof” then Z wave since the same devices that will runs zigbee will probably also be able to run Google thread in the future. More and more Zwave is standing out on its own. That may not bother you, but it’s something to be aware of.
My personal feeling is that while both Crestron and control 4 are mature, reliable, full featured, stable systems right now, there’s nothing in the SmartThings price range that can say the same.
My own guess, and it’s purely a guess, is that by the summer of 2016 there will be a number of home automation candidates with quite good systems in the $200-$500 per room range. HomeKit/Insteon will be one. Works with Nest will be another. Eventually something based on Google Thread may be a third, although it may not be fully baked by next summer.
It’s quite possible that Samsung/SmartThings Will be another candidate, perhaps even the Google thread candidate, but right now it’s not there yet. Reliability, in particular, has just not been there for me.
I’m waiting to draw up my own candidates list until around May, just because I think there will be several new offerings to consider at that time. So I limited my only stage one investment now to specific use cases where I would see an immediate payback and where I would be willing to replace all of the phase 1 equipment in the fall of 2016 if I ended up going with a different protocol. But everybody approaches these projects differently.