Thanks Chris,

I've been tuning a stored procedure that itterates down a tree structure  to accumulate a list of ids within that structure and then returns the details associated with those ids.

I experimented with temp tables vs table variables and found that some parts of the procedure were faster with temporary tables and others were faster with table variables.

In this scenario I was interested in the overall performance of the procedure.

I spent quite a bit of time with Excel plotting the impact of one vs the other as the tree structure grew more complex.

In the end I decided that for shallow trees table variables were better, but for deep trees it was temporary tables that gained the edge.