So if you take 'block runner' perk (70 block in the left tree), you can sneak must faster. But if you hold a shield up whilst sneaking with the perk, you sneak faster than you walk (not as fast as running though). This means you can close the distance much faster to your target, I recommend the sneak perk that removes the sneak penalty for running/moving fast.

I've yet to get the shield run perk (100 block) as I have no perk points left and it takes me ages to level up now (level 71). You may be able to run with the shield up whilst sneaking, I doubt it though.

Thoughts?

Also just tested out speed with shields, having a heavy shield, a light shield or no shield is the same speed.