I've been running Neptune controllers for almost 10 years and only had one problem that they took care of promptly. Their tech support if you need it is fast and great, and building up a controller for your tank does not kill your wallet. It is modular for much cheaper than the Profilux would be if you ran another tank. The quality is high, though not top end as they had to find a middle ground to target more people. They are aggressive with updates and new prducts, and were the first to announce and release the Vortech control of all of the companies. Complaints of their product would be the USB buss cables...they are not as easily found online for long runs like the Ethernet Profilux uses or the data cable RK uses. I currently use 2 Apex Jrs on my 2 tanks and have used the full Apex.
Reefkeeper would be the last of the ones you list. They have no Vortech control and have no plans for it....if that is a must have for you it rules them out. Last I checked they are still battling the SL2 salinity issue which has been going on for what has to be 2-3 years with very few updates. Was not a module I used, but again if it is a must for you it seems to be open ended on when they will fix it. Things I do like about them....the head unit is a bit more attractive than the Apex plus you can change display colors. Non issue for me since I need no HU anymore. I also like the package since you get 2 4-outlet power bars instead of APexs single 8...however I don't like the low power handling of (3 amps) of half the outlets.
I have very limited experience with the Profilux. Quality is high, and I like the random control of the Tunze. I assume that is also possible with the Vortech. A lot seems to be tied to the main unit and an extension box is kind of pricey last I checked into it. Meaning it is not as modular as the RK or Neptune. You could spread an RK or Apex out over an entire house and the only expense would be buss cables.
I have no experience with the Reef Angel. I like some of their cheaper prices. The ability to program whatever you want with the free ware or open software or whatever you call it is nice, however I have never felt at all limited by Neptune. Matter of fact I use only a fraction of its capabilities to control lighting, temp, reactors etc.