Hello Dp,
This is quite an old post but in case you are still curious.
X7 is actually ISAW Extreme.
http://www.actionpro.de/en/newx7/
http://isaw.com.ua/en/Isaw-A3-extreme.htm
I got both the X7 ( now dead, bad unit I guess ) and the ISAW A3 Extreme ( i got 2, in case 1 went bad again....LOL )
My advice is , get the GoPro HD3+ Black and set Protune + Camraw and be happy. Choose its Dive Housing 60 meter rated or its the older HD3 original housing actually under a new name. Yeah, get the LCD BacPac too.
The X7 or ISAW A3 Extreme has built in LCD screen and they are so dark, you go blind underwater with it, unless it is a night dive. You can't remove the LCD screen, it is there permanently.
The 1080 50p ( or 60p ) resolution on this camera is very bad. The 25/30p is good.
At 50p its like scaled up and not true 50p.
Its so called UW white balance the Aqua is useless for your kind of dive.
I have not dove the X7/ISAW beyond 10 meters, was only doing shallow test dives and retire it after I seen the LCD screen is so dark and I can't see anything. Not having an equivalent CamRaw like the GoPro is another turn off for UW use, its hard to color correct it later in post.
Its exposure is jumpy too, not so smooth. Kind of small flicker at times.
Wifi smartphone or tablet Apps , the GoPro is light years ahead.
Hope that helps.
I have the Sony Action Cam AS100 too, if you considering it.
Again for UW use, stick with the GoPro HD3+ Black and be happy.
Happy shopping....