It is somewhat fluid. Yes it is considered Sorrento Valley however over the past few years there was substantial development to the north of UTC so alot of traffic goes there now as well. Even all the biotech on North TP road “maybe” considered. For instance my engineering firm is at the Tech Center which is Mira Mesa exit off of 805. Smack in the middle of GT.
Again, I think you will find both areas have many good qualities to them. Also I tend to think if your commute is downtown CV is less of a commute.