Nocturne is very leash dependent early, but he snowballs just as hard as any Fotm jungler in my opinion. If you can successfully invade the enemy's camp and get a significant lead on the enemy, you will keep going if you don't play stupid.

When I play Nocturne, I take a lot of gambles. With the tankiness from Randuin's Omen and movement speed from Duskbringer (Q) I can usually escape. THIS IS NOT A GUIDE FOR HIGH DAMAGE ASSASSIN NOCTURNE.

An example of a gamble I might take is sneaking into a lane behind an enemy tower and having the laner push while I wait to execute. Nocturne is like Shaco in a way that Psychologically screwing over the enemies is just as important as physically. People should be terrified when you're MIA.

The flow of Nocturne's abilities work extremely well with the flow of lanes. For this reason, lane ganks are your best friend. My absolute favorite gank is sweeping through the bush in bot lane after the support has cleared the wards. The pure terror from the ADC is delightful. You can brutally destroy both adc and support before they have a chance to run. Then you get to watch them rage. Fun right?
This gank usually plays out like this: wait for the enemies to push past your point in the bush just slightly, then tag them with unspeakable horrors (E) by the time they start to run they're feared. Then you and your allies go to town. Now since you're building tanky, the enemy might have an opportunity to run after the initial damage so NOW is when you use Q. It does give the bonus damage, but if you use it early, you lose that stickiness that Nocturne needs. Plus without it your only gap closer is Paranoia (R) which is a very long cooldown and great for initiating team fights.
This combo can be translated to almost any lane, but Mid is the hardest lane to gank. Typically for mid, I come in from behind and make sure there are no creeps between the enemy mid laner and my mid laner. I can tank the creeps easily, and this allows very easy initiation for my laner.

Pros:
-Great Initiation
-Incredibly Terrifying
-Counter Jungles well
-Lane ganks
-Snowballs

Cons:
-Weaker early game
-Gets shutdown/countered easily
-Relies on follow up cc
-Easy to play Hard to master