I actually use Crobat quite often, with a fairly defensive spread, except for speed which I run with fairly high speed EVs (just enough to outspeed what needs to be outsped).... It walls quite a bit. With the massive amount of fighting types this generation, the rise in a few grass types, and the always present bug attacking threat, Crobat actually walls quite a bit, and does his job quite nicely. Multiple times have I come across a 1v1 with Crobat being my last pokemon and have stalled out things like Skarmory or Ferathorn by just Taunting and Roosting and Brave Birding once the enemy runs out of PP on attacks.
The downfall is the fact that psychic types have made a slight rise. That and Rock, Ice, and Electric have always been common attacking moves... This makes it difficult in knowing what you can switch Crobat into safely, however his high speed + U-Turn make up for it, being able to do hit and run techniques on pokemon like Reuniclus to deal some damage as you U-Turn out to a dark type or something to finish him off.
Sawsbuck does not bother me when I have my Crobat.
He is definitely one of my favorite leads, between him and Aerodactyl, I feel like I can't give those 2 up when deciding on my team lead.