Oh right, cameras… added those. 
I run HomeSeer 3 Pro on a headless Intel NUC6i3SYH with 16GB of memory and a 256GB M.2 solid state drive. It is admittedly overkill but I figure it will let me re-purpose it later if I need to. A growing number of people are installing it on RPi, but some plug-ins don’t work in the Linux port. I find their HW controllers a bit pricey for what you get. Their annual “Black May” sale is going on right now, all their software is 50% off. I bought mine during a November 50% sale. The “Pro” version gets you HomeSeer 1st party plugins, and other stuff like their (normally $60) firmware update tool that lets you update multiple devices at once, Z-Seer to see the routes devices are using, and a couple other things I think.
Home Assistant (aka HASS) is another nice option for the open source community and it was recently acquired by Ubiquiti which could be interesting. It is supposed to remain “independent” after acquisition. HASS wasn’t as built-up when I bought HomeSeer so I’d probably compare them a bit more if I were to start over.
Even though HomeSeer requires purchasing (or writing your own) plug-ins for a bunch of integration I decided that was ok for my needs. I’ve spent a few hundred bucks on plug-ins and generally speaking all of the authors are extremely responsive and do their best to provide updates with new features and bug fixes. I also wanted something that wasn’t reliant on remote services and HomeSeer is entirely local unless you’re activating a plug-in license or if a plug-in has a hard requirement on a cloud service like ecobee as they do not allow direct control of their devices other than via HomeLink as far as I know so you must go through their service API. I think SmartThings still needs Samsung’s services online to work, but maybe that’s changed by now.
When I started I was looking for something that offered (even through plug-in purchase) a wide array of integration and a large degree of customization. A couple coworkers had HomeSeer so I got to see how theirs worked ahead of time. HomeKit, SmartThings, and Wink just weren’t (and still aren’t AFAIK) offering the level of sophistication I wanted. That’s perfectly fine, I see them built more for the consumer just getting into the area of home control/automation rather than the prosumer geek looking to take things to another level for fun.
I do my best to stick with Z-Wave or hard-wired devices when possible to keep “noise” off the Wi-Fi spectrum, but there are some Wi-Fi exceptions (ecobee, Ring, Rachio, Sense). I also like knowing if Wi-Fi is down the home’s extra functions remain functional. ZigBee channels overlapping with the 2.4GHz Wi-Fi channels is another big issue for Hue. I moved my Hue hub to the ZigBee channel which had the least overlap here and the bulbs became much more reliable/responsive.
I’ve tried to approach home control/automation with an opinion that it should enhance the home, but not force people to re-learn habits. My friends and family should be able to come into a room, hit a switch in the way they expect, and then get the kind of reaction they expect. Hue bulbs can make this a bit challenging. For example if you turn off a bulb in their app but the wall switch is still “on” it can really confuse people and I don’t like it. I’ve coded events in HomeSeer that essentially are “If family room switch is on AND Hue Bulb is 0%, AND family room switch upper-paddle is pressed, THEN set family room hue bulbs to 100% and default color.”
The remote sensors are what sold me on ecobee. Our heating and cooling zones span more than one room and the sensors have helped us average out the temps much better. It’ll never be perfectly balanced without adding more zones or electronically controllable dampers, but it’s better than it was.
Hah… that’s mostly what our indoor ones do as well. Oh look… the cat is sleeping still.