The focus light on the sea and sea is ok but I would recommend a sola or similar just because they put out much more light which you will appreciate on night dives. Also do not underestimate the value of two strobes, probably more important than the brand. I would also say that manual is much easier than it sounds, and you are likely to get much better results than with ttl. One knock on the inon, though I have no experience with it, is the size of the adjustment knob. The sea and sea is easy to adjust. Both are good and certainly if you stay with point and shoot more than adequate. I take two sets of batteries so that one is charging while the other is in the strobes, change after every dive, the SS is really easy to change, number of shots is then no longer relevant. have found that the s95 won't last through 2 dives anyway so might as well change all the batteries, maybe the s100 has a better battery.