This week I decided to focus on some of the long-outstanding issues with IntelliSense in Management Studio. While I know many of you are using 3rd party tools like RedGate's SQL Prompt, not everybody has that luxury – in my case, I can't justify a license for every single server I touch, since I can't connect to every environment using SSMS remotely. While I like the idea of IntelliSense, it gets in my way more than it helps, so I always disable the feature.
#614130 : Intellisense doesn't work with CAST – Simon Sabin
#478568 : SSMS Gets Blocked and Locks Up During Index Creation – Adam Machanic