The annoying thing about the Time Out guide is that everything is listed thematically (Bars, Restaurants, Theatres, Galleries, etc), which means that when you are actually there, you spend a lot of time flicking about through chapters trying to find stuff relevant to the area you are in. Areas are also rather vaguely defined too, which doesn't make the task any easier. (Other guides tend to group things by area. Mostly when using a guide you want to get an overview of an area: what bars, restaurants, attractions there are; we found this sort of format much more user-friendly)
We went to a few recommended restaurants which were average at best. Friends in Rome took us to much better places: I'd expect Time Out to have more of an insiders' view. The lack of any sort of ratings system also made it hard to know exactly what sort of place you were going to: formal/informal, etc. Essentially I wasted a lot of time looking for recommendations when I was better following my instincts.
In mitigation, some of their historical/cultural information was reasonably accessible and readable, although often content is sacrificed in the attempt to maintain their trademark hipper-than-thou tone.