I asked myself that same question all the time.....stills or videos?
I may never find an answer to that question.
Here is what I know about myself. Diving 20 times a year isn't going to develop any skills on taking underwater photos. So an SLR and a point and shoot won't be all that different for me. In fact, point and shoot might help me more.
So, my last purchase was done based on the objective of
1. being able to take mostly video clips of about 3 minutes (30 minutes if I feel like to
2. very easily take stills
3. have underwater casing, from manufacturer preferred (yes, I like having lower budget)
I got Canon Vixia HF M300 and Canon Powershot SX230. After some testing, I decided to take SX230 with me.
Yes, I know all you SLR lovers who thinks a cmos sensor is not kosher....well, it worked perfectly fine for photos. The sensor was great in low light condition. That bodes well for deep dives, caves and night dives.
Videos, however, can't take advantage of that for some reason (why canon, why??), so for video, what you see if what you get. It records at 1080P, but it's only at 24 fps (a lot lower than the M300...but you just can't compete with a real video camera)
I find 24 fps to be enough for underwater videos. Things just don't move fast enough to make a difference.
It has 14X optical zoom, but seriously, you'd be using up to 3X in the water (5X at most). 14X will come in handy when you are on dry land.
There is a GPS chip inside. Geotagging can be fun.
Best of all, I can shoot, adjust setting all with one hand.
Of course, new models are coming out every other month. I'm sure a better candidate that fits the description will be out soon.
I hope that helps.