Help me make a choice.

If someone were going to give me one of the two I would take the 920.

The 920, unless the 935 is in your budget.

The 920 by a longshot.

I'll go against the rest on here, hands down the fenix 5 - I went through 3 920s, yes 3! Too many issues with it. I liked it, when it worked. Upgraded to the fenix 3 and now the 5x, and it's been a great watch. Expensive, but IMO & experience, more reliable and for that fact it's worth the $$ to me.

This is my opinion as well.  I have a 920 which does and has served me well but if I were to need a new watch tomorrow, I'd move up to the 935.