Just got mine today and I have mixed feelings. I'll show some pics before I get started as they will explain quite a bit I think. Default optics on these LED modules is 100 degrees. There are 70 and 40 degree optics included in the package.
Now, on to cons of the setup (this is just my opinion so please don't get too flabbergasted).
Well, now that you've seen a bit of the setup. I'll give you a few details of how and why I've got it setup the way I've got it setup. So, I ordered a three module unit, but only have 2 modules mounted because one of the modules was missing one of the inner frame connectors so I couldn't use one of the frames (easily amended w/ a call or e-mail to the shipper... I hope). So, that answers that question. I have them roughly 11" over the water. This is on a 48" x 24" x 16" tank, but the last 8" of length nearest the wall has the overflow and my Tunze pumps in the corner. So it is shaded so I'm not trying to light those parts so I was thinking 3 modules would be perfect.
Although I don't have the third module on, I can tell that three modules won't cut it aesthetically for me. The light output cannot compare to the uniformity and beauty of my MH fixture (maybe it would match or even beat on par values, but to my eye, it just doesn't look right, looks dim and generally feels like light coverage of the tank has dropped 50-60%). It is too spotlighty for me. Colors are also quite different and I'm just not happy w/ it no matter how much I adjust each channel (A,B,C,D all correspond to different LED spectrums).
Another thing, the line management is absolutely horrible, I like a clean looking setup and I just can't stand the lines that resist good organization. The little line brackets that they include with the kit are loose and wobbly. The actual mount for the control is loose as well. There is no way to actually securely mount the wireless/wired controller, it just hangs on the plastic screw loosely. The clean look I am striving for on my tank went out the door once I started trying to hook everything up... Some people may get it looking a little more organized, but doubtful it will look that much better (this may not be as big of an issue if they begin using black aluminum framing so that the wires don't stand out as much).
Pros:
1. Different spectrum LEDs completely adjustable.
2. Frame mount is very adjustable if you order enough frame mount kits.
3. The LED modules are very adjustable in terms of positioning and you can focus light on a specific spot (this is somewhat of a minus for me as I hate the spotlighting effect)
4. Wireless control (kind of, you still need to wire in the wireless controller to power it) of up to 16 modules.
5. Cool dawn/dusk effects and you can program your own light schedule
6. Modular so you can add on more and more units to suit your needs (up to 16 w/ one controller)
This is a shot of my tank w/ MH and T5's, I just don't think that I can ever get that w/ a LED setup that uses optics.
Well, overall, I'm actually a bit disappointed and most likely will be returning them and will continue to use my inefficient MHs.

Oh well, it seemed so promising, but guess I'll continue watching.
But hey, maybe they will grow on me in the next couple of days.
Cheers,
John