That is the unit I am waiting on to be released. I like to see what issues there are before being the beta tester, :lol: I used to use a Aquacontroller 3 when they were first released and loved it. One thing I like to is that out of the box it has 2 PH probe inputs (Cal RX), ORP input can either be an ORP input, or a second pH probe - Galvanic isolation on probes (no probe interference issues like the competition) and Net interface. No need to buy another module for those. Also the software will be programmable via web interface via XML and iphone app (for those of us using iphones). Also has aquasurf built in so full control of Tunze powerheads (and vortech's via hack

, but the vortech controller is already awesome). Don't get me wrong I really like the RKE also, but you really cannot compare them yet, because no one has actually used the Apex yet. Just IMO for my needs, dollar for dollar this will be cheaper for me.
Here is the link to the main thread. Curt (clp)from Neptune has been keeping everyone posted on features and release ETA.
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1612322
Some details from that thread:
AquaDisplay Features
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- sleek and stylish case.
- compact size 3.40" x 4.05" x 0.65".
- mounting holes for easy attachment to wall/stand
- 7 mechanical buttons for speedy access user interface
- 128 x 64 Backlight display
blue background with white characters.
high contrast, excellent display quality
- Displays datalog graphs
- 4 Highly customizable status displays
placement of probe names and icons can be selected by user
can scroll manually scroll between different status screens
or automatically scroll through them.
- user adjustable contrast and backlight settings.
- backlight can be dimmed at night.
- Audible alarms
User selectable tones/songs for different warning/error types
- multiple displays can used on one systems.
all remote displays have the same functionality as the primary display
(i.e. can configure, graph, initiate feed cycles, etc. from all displays)
AquaBus
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- High reliability
Robust Error Correction
Industrial quality bus which uses a differential drivers
(unlike competing products which use an unreliable I2C or TTL bus)
- Either daisy chain or star wiring topologies are support
- Supports up to 240 different modules.
The most expandable Aquarium Controller.
- Bus cabling may be as long as several hundred feet.
- protocol allows all modules to be upgraded from the base unit.
no unplugging units and connecting them to a PC (extremely simple)
- Plug & Play
system will automatically recognize new devices and configure them.