On the topic of top lane udyr, I'm liking hydra more and more as an item to rush against any lane that can't burst you. Gives insane sustain, damage and waveclear all in one item, and you can pretty much go pure tank from there. Triforce is better for single target, but hydra gives wave clear, which is something tiger udyr lacks without spending tons of mana or skilling R.
Of course if you get absolute free-farm/fed, having both is very nice, but that leaves you with only 3 slots for defensive items which are also extremely late. The one game I did get both I was legendary with triforce hydra randuins FH and mercs though, so YMMV.
I'd imagine the 3 defensive items of choice on Udyr would be FH, randuin's and bulwark though. Locket is nice, but it's kinda a mid tier defensive item when udyr really likes the high tier ones(scaling with turtle is better with slot efficient items come lategame) .
Also, one more thing is turtle usage. If you aren't dying, you should be using turtle less, and more bear/phoenix/tiger. IMO in teamfights you want to use turtle as little as possible that still allows you to do your job. Turtle is an amazing skill at reducing incoming damage, but if everybody is dead and you're still at 60% life, maybe you could've killed somebody a bit faster or stunned another person.