Today I made ( for the first time ever, even outside of TES ) a Thief character.
After my first impressions I must say that Sneak combat feels much more complex and deep than Melee and even than Archery.
You can actually hide better in dark places( to the point when the enemy can walk past you without noticing )
The arrow distraction is very useful and many other things make it feel better than most other combat systems.
How well you thing Sneaking is in Skyrim ? ( And realistic ? )