Perhaps I'm asking the obvious, but what exactly is the purpose of William Grimes' Diner's Journal in the Times ? It seems like it's somewhere between a press release about a new restaurant and a full-fledged review. Why step out of the standard review format of awarded stars, full descriptions of the food, and a clear p.o.v. about visit-worthiness ? I've been wondering this for awhile -- has anyone else ? I always find the Diner's Journal pieces frustrating -- a tease.