Swimming: arms or legs

No....all of the fish who say how important kicking is can kick a 100 faster than 90% of the people here can swim one....and if you find yourself racing them,  they would also like you to not work to develop a kick.

Think it's a bit of a loaded topic. Do want to be efficient at kicking so that the energy put in is effective at doing something, but think many mistakenly take that to mean not to do much of any kicking since that sounds like it may not matter. Especially in the longer races, the fish will kick only a little, but their efficiency will be incredible and they get a lot out of a kick even though they only put in a little effort during the race (I'm looking past specific situations right now that many on this board will not really encounter). Trying to determine what is "efficient" is a really good question. And what it takes to become anyone's type of efficient could be all over the map as people will develop quite differently with such a variety of starting points (and other reasons). Pretty safe to say that hardly going anywhere, or actually going backwards could probably stand to do something about it though. 

There is not a single person on this board, except for a very select few, who would not become a better swimmer by doing more kicking and learning to kick better.  It's not fun,  it's not glamorous, and it basically sucks all the way around as training.....but it's necessary to become better/faster.

I had some of the same questions and was resistant to work on my kick until this past winter. I finally got some good coaching and even though I fought them a bit at first, they forced me to work on my kick. A good kick really does help with the overall stroke.

My conclusion was this, train like a real swimmer, then race smart. If you don't work on your kick in training, your kick won't do you much good in racing, if you train the kick like a real swimmer does, that does not mean you have to use all of it in a race. 50% of a well trained kick is still much better than an untrained kick in a race. 

So I kicked a lot in training then I dialed it back a bit in my IM based on RPE so my legs were fresh when I got out of the water. 

Shhhhhh!!!  You know damn well that swimming is not that important compared to bike and run.

Most will be faster/more efficient with a wetsuit because of the better body position....but they still can't beat the folks who kick well, it just closes the gap a bit.

I still stand by my original post. Note that this doesn't mean I say it's not worth it to improve your kick some - it clearly is, and the better swimmer you become, the more important the kick becomes.

But for anything short of a FFOP swimmer trying to get better - it's almost entirely about the front-end.  You do NOT go from one category to another in triathlon swimming (like BOP to MOP)  by working on the kick - you get it by improving your pull. The kicking is secondary to the pulling.

And those fish absolutely do NOT need a kick to go fast. They'll lose a small % of speed, yes, if you remove their kick (like pulling with a buoy), but they will still remain very fast sans kick. I bring this up to reinforce how important the pull is. In response to the OP, which is more important, it's perfectly correct to say it's 80%+ arms for swim speed, and 20% or less your kick power. Test any of the fish or folks on this very forum or elsewhere with swim+kick vs swim+no kick+buoy and it'll be very clear. Even with those dead spots and other inefficiences that are introduced while swimming without a kick.

But again, don't take it from me - take it from Sheila Taormina, ex-olympian and high level swimmer, who felt it was important enough to write an entire book devoted entirely to the catch and pull of the upper body, while clearly saying freestyle is 80% propulsion from upper body pull and 20% body position/drag reduction in her Swim Speed Secrets book aimed at triathletes/intermediate swimmers.

http://swimspeedsecrets.com/about/