I ordered the 10-BAR housing for my new Sony Nex-5n based on the huge difference in price between this and the more expensive options such as Nauticam. Although as is often the case, you get what you pay for...

The housing itself is not overly bulky, although it is pretty heavy when out of the water.
The double o-rings ensure a very snug fit between the clear back cover and the main body, so i have a lot of confidence regarding the housing's water integrity.

The buttons can certainly be a bit fiddly (i wouldn't like to try with thick gloves) and are very close together in the main cluster. I can't help but think that if the cluster buttons were made as differing lengths, it would be easier to access them.

By far the biggest faults i have encountered have been:

1: the recess into which the flash pops up slightly fouls the back edge of the flash itself, meaning it can move forward just enough to disengage the flash. On a few occasions, i couldn't quite get the flash to fully extend, meaning i couldn't use it.

There are two solutions to this. Either you can hold the flash lever in the up position whilst taking a shot or, more drastically, gently file down the area that is fouling at a 45 degree angle (just enough to allow the flash to remain in place without having to constantly hold the lever).

Of course, taking a file to a brand new housing is not something most people would be comfortable with!

2: the second, and by far the most irritating problem i've encountered (and still haven't quite solved yet) is the lack of a suitable contact between the housing control wheel and the main dial on the camera.
The tolerance between the two is so fine that it regularly doesn't turn the dial at all during a dive (meaning you lose access to the shutter and aperture settings), or it touches too much, resulting in constantly cycling through the menus or functions without stopping!!

There are a few other small quirks, such as the block for attaching the housing to a strobe tray. I'm finding that, due to the weight of the housing, it has a tendency to turn slightly on my Ultra-lite tray. This results in me having to try and tighten the securing nut quite often during a dive.

Also, the decals on the 3 man buttons (video record, playback and the direction arrow on the control dial knob) are stickers, rather than being etched into the button. Recently the direction arrow fell off the dial knob button and the playback sticker is about to follow it.
I don't see this as a major problem as by now i'm familiar enough with the buttons that i don't really need the stickers any more.

In conclusion: if you can afford the more expensive housing options such as the Nauticam, then that's definitely the way to go, otherwise, the 10-Bar will do the job for those on a tighter budget, provided you can live with the quirks.
Of course, it may be that i was unlucky with the flash and control dial problems with my particular housing and no one else has encountered this.

I can't help but feel that with a little bit more thought at the design stage, this could have been an excellent housing rather than a good, but frustrating one.

Alan
Thailand