Robin, at one point or another I think all my videos have been posted here. If not,
www.youtube.com/leabre
I used the Flip Utlra HD for my first four videos, and the JVC for my 5th. The fact is, I like them both, but each has its strengths that would make me choose one over the other in different circumstance.
What I like about the Flip:
* Replaceable batteries instead of recharge only. For diving 1 or 2 dives where I won't accumulate more than 120 minutes of video, this works great.
* Better low-light capture. I like to shoot video of the conditions and surface area of my diving locations that I use in the opening sequence of my dive videos. Most of my diving in in night, so low-light is a must. Doesn't have to be perfect, just close enough. The Flip easily wins in this department.
* It turns on very quick, and off. So if I turn it off and see something that I must film there and now, I can turn on and start recording very quickly with the Flip and not miss the shot.
* I use Sony Vegas Studio for editing the video. It works out of the bod with the Flip codec.
What I perceive as disadvantages of the Flip:
* Built in memory. This means if I want to use on a dive vacation, I have to bring either a laptop with me to download the video to clear some space, or bring multiple Flips (which is what I've chosen to do).
* Image Stablization: none. Recording 720p at 30FPS and no OIS leaves movement looking blurry. Really blurry at times. Not always so noticable on Youtube but on a 52" HDTV it can be nausiating.
* Light sensitivity: I think it saturates too easily. Many of my night shots have been overly saturated with just a 15w LED too close (5 ft). I cannot use my 21w HID or there will be no video at all to keep. During day dives, this is not a problem, this camera records wonderfully with natural lighting. At night, I have to be careful.
* Focal distance: Focal distance is about 3 ft. So any closer and it's blurry with the built-in lens. Not a problem if you're aware of it and edit it at the point it becomes too blurry. But not closeups for smaller creatures.
What I like about the JVC:
* Uses SD cards so I can swap out cards to record more video on longer dive trips where multiple JVC's or bringing a laptop is impracticle.
* Makes better use of the storage than the Flip. Where I record so much time per 100 MB, 500 MB, or 1 GB on the Flip, the JVC seems to record about 10-15% more minutes in the same MB capacity. That may not be scientific since I'm not recording with both Flip and JVC side-by-side (I build a two-handle tray that allows me to do just that and I will shortly), since both advertise 120 minutes per 8 GB, I find the JVC consistently records more minutes than the Flip.
* Image Stablization: JVC has some rudimentary IOS that helps a bit if you're careful, it's still not perfect, but far better than the Flip.
* Records 720p @ 60 Hz. Combined with OIS and 720p at 60 Hz, movement is near crystal clear with the JVC, but that can make one nautious of the movement is too fast.
* Can record @ standard and 1080p. At 1080p, it records 30 Hz, which makes it much like the Flip with regard to motion blur, and depending on light sensitivity, the grainy can be far more pronounced. I keep my recording at 720p on the JVC.
* Macro feature. In portrait mode, the JVC has about 1.8 - 2 ft. focal point to infinity, still closer than the Flip. In macro mode, you can get about 1 inch to 1.5 ft. Any closer or further, it blurs out. It is easy to switch the Macro mode during recording.
* Due to its poor low-light sensitivity, it ends up filming night dives with just the right amount of light to not saturate (at all) with my 15w LED and in shots with my 21w HID it appears to record very close to how my eyes see it.
* JVC has a wider field of few than the Flip. I have a 12 ft. long couch in my living room and if I'm standing 8 ft. from the center, the Flip will record something like the center 9 ft of it but the JVC will be able to barely fit the entire view of the couch into the film. It helps under water, you see more.
What I perceive as disadvantages of the JVC:
* Non-replacable batteries. It's nice that I can change the memory card, but the JVC will always have to be charged. So... for many dives or long dive trips, like the Flip, I'll have to carry multiple JVC's or miss a dive while it charges (if the boat has a plugin). The battery lasts longer than the Flip, but not long enough to record 2 full hours of video. It takes about 1 hour to fully charge a battery.
* Low-light sensitivity: sucks. At beaches, during night, the Flip will pick up what light it can and it generally does a decent job (view my Vets night video (first 30 seconds) for a visual reference). That exact same seen, shot from the JVC is pitch black. While a disadvantage above water, it is a wonderful advantage in-water.
* Time to power up. It is quick, but not as quick as the Flip. I'd say it takes about 3 seconds to power up and begin recording. That's enough to miss some shots if you are swimming around with the power off.
* I use the Sony Vegas Studio software for editing the final video, and it requires Apple Quicktime to be installed for editing, it does not recognize the JVC codec out of the box
Shortcoming of both:
* It isn't the cameras fault, but Ikelite's. They don't make a two-handed tray to assist with stability and to provide option for two lights. The one light option they provide is sufficient, but quickly becomes irritating when you see a circle rather than even distribution of light in the final video. I fabricated a two handle tray that can also serve two lights that seems to help in this area.
In short, I like both cameras. The JVC is far superior in-water night dives due to its resliance to light saturation. I don't have the JVC in my posession currently, but if I did, I'd prefer to JVC over the Flip if recording above water sequences wasn't important. I do not use the included software for editing, I use Sony Vegas Studio. Vegas works with the Flip Codec but not the JVC one (even after installing included software).
There is another camera that Ikelite makes a housing for, the Kodac something or another. I haven't used the camera but it seems to allow for changing batteries and memory cards (a proprietary battery tho) and records 1080p (30 Hz) and 720p (60 Hz) and has OIS (to what degree I cannot comment but most others think it is better than the JVC).
I do not think you can go wrong with the Flip or the JVC.
[Edit] The JVC can take stills but they are nearly impossible to get right. They tend to be blurry. For in-water stills, the JVC isn't it.