I own/owned both Apex and Felix Smart,
My kids find the Felix app "IFTT" much easier to use than the Apex, however, I've now taken the Felix off my nano reef and given that job back to the Apex. Why? I love power monitoring and having a display tank side without having to access my phone. With one push of a button on the Apex display, my 14 year old activates feed mode to serve her crabs weekly delicious treats.
The compactness of the Felix is hard to beat though so I chose it to control my Red Sea reef tank at work and it's going great for over 2+ years now but now my personal Felix now manages my friend's micro garden. I have the version that came with the Seneye and the 360 camera and so the Seneye gives us PAR and air temp and the camera allows us to see the leafy greens growing.
Neptune customer support is hard to beat and second to none and I can rely on their ticket system but again the proprietary Apex language has scared my eldest kids from the reef tank, but due to simplicity, my nano reef is pretty much now neglect proof. Only 2 water changes in nearly 3 years and my devils hand leather coral still thrives along with inverts though nitrates are off the charts.
Communication with the Felix team started off very encouraging, but now has room for improvement. Being in Calgary, I've also had the pleasure of meeting Tom, the CEO/Founder and was sold on his vision, though I knew the challenges of every start up, I encouraged him and have nothing bad to say as he did listen to much of my first hand user advice (except power monitoring). Kudos to the Felix for providing a suite of sensors especially Humidity which I've been begging Neptune for since Terrence was around... Tom Listened! now I'm begging Morgan at Neptune who now says maybe I can use the ASM if I find a compatible 0v-5v sensor and attach a BNC connector but I will get no support... This is why I donated the Felix to help my friend feed his family with his micro garden.
Other things off the top of my head about the Felix? Hmmm...The colour changing scrolling lights (which can be turned off) look cool and act as a heads up display when the system looses internet connectivity as it switches from a scrolling blue to white. Bummer that they are low on stock and the suite of sensors, like I can't get an additional pH nor ORP probe as currently almost all kits are also sold out. To be honest, I'm guessing with the economy in Canada affecting retailers, manufacturers and hobbyists, Felix may be in "staying afloat" mode as I haven't even been able to get through to Tom on my most recent few attempts. Hope he makes it through this tough time because I really like the product and have been impressed with the new version released.
In summary, would I buy the Felix saltwater system aka Kai today (if it were available)? Unfortunately No! I just can't justify paying such a high premium i.e. ~C$900 Apex A3 vs C$1,799 for the Kai Saltwater and Neptune's market/product presence is much more consistent and certain. So if I can't find a way to integrate the Atlas Scientific humidity probe into Fusion via the ASM module, I'll stick with my current standalone humidity sensor for my own personal Saltwater Tilapia Micro Garden I'm setting up to feed my family. Tip: Tilapia are euryhaline and are the overlooked gem that I'm using to encourage my friends to get back into the marine hobby - grow saltwater fish that you can eat, not just look at
Well, It's a snowy Saturday in Calgary and am gonna go shovel now. Hope this helps...
Still Reefing.