(Constructive) A Naut player is somewhat concerned.
First off, I'm very pleased by the new tank item and absolutely love the idea behind it. It's 10/10 and I applaud the balance team for coming up with a unique and interesting way to help jungle tanks come back into viability. With that being said, the Naut changes are somewhat concerning. Now I have a LOT of games as Naut across two seasons and like to think even if I'm not a challenger level Nautilus player I know what is good and bad about this champ and how to make him viable without being oppressive.
In mid season 3 there was a time where Naut was actually very strong, but for the wrong reasons. If he got rolling and was somewhat ahead of the enemy jungler he actually became a great duelist because of the high damage and tankiness his W provided. Riot, very understandably, does not want this to happen again because Naut and Duelist should never be in the same sentence unless that sentence is, "Naut is among the worst duelists in the game."
In season 5 it's no secret that Naut is borderline unplayable. I used to be able to clear in a passable manner before they buffed up the jungle a bit but at this point I can barely do 3 camps before having to back, and going back to JUST get trailblazer is a very sad Nautilus as his 325 movement speed means ganking without boots is very difficult.
The changes go in the right direction. Reducing his E cooldown will make jungling somewhat easier and it having a lower CD at higher levels means his teamfight will be stronger. There's just one problem, his late game did not need ANY help at all. Once Naut gets a few items and levels he's an absolute monster regardless of if he has juggernaught, randuins, banshee or juggernaught, locket, frozen heart. The buff is appreciated, but what isn't is the changes to his W.
Nautilus' shield already gets decimated by the camps and getting more than two swings in requires abusing his animations to get damage when his shield is down. Reducing his damage is understandable if you're buffing his utility, the main problem is his utility doesn't need buffing and his early damage did not need nerfing.
Nautilus does not build AP I don't know if this needed to be said, but it has been now. Nautilus has scaling only on AP, and given that no Nautilus is taking AP runes into the jungle, nerfing his base damage is only going to weaken his clearing. E hits in waves, and unless you position the mobs well you aren't going to get more than 2 bursts on each one, so while the extra damage there is welcomed, the loss of damage on his bread and butter ability is not.
If you change his preferred maxing from W to E you inherently ruin his threat patterns in ganks and early game fighting. Nautilus should be a threat when his W is up and he relies on that ability to effectively tank because if people let him sit on carries with that up he will do surprising damage. Not to mention this doesn't solve the issue of his first clear which is his biggest problem already. Once he gets trailblazer and some levels in W his clearing his passable and it's really just not dying to a sneeze trying to take wolves because he chugged both pots on blue/gromp and is down to 20% again on his first clear that needs addressing.
Nautilus is in a bad spot and there should not be any power removed from his kit until it's tested on live. If Nautilus and tank junglers can, somehow, overthrow the current holy trinity of junglers flooding games and forum posts alike, is that really a bad thing? Buffing his strengths and increasing his already crippling weaknesses are not proper choices. If anything, buff his early W damage (ranks 1-2) and make it so it caps out lower to compensate for his E getting a reduced CD if Naut proves to be doing too much damage mid/late. Alternatively give his W increased damage vs monsters to make his clearing easier.
Getting trailbalzer+the new item will still cost around 1350 gold.. Which means Naut will have to farm 1350 to just clear efficiently, which leaves him with no boots to gank with.