It honestly depends on the restaurant. I went to three restaurants last year, ranging from so-so to great food to spectacular.
I can't remember which price point it was at now, but we had a 3 course dinner at Quince (£20, I think) and it was average. Great service, but the atmosphere of the restaurant just wasn't there. The food was also unmemorable.
North Road restaurant, on the other hand, was really good. It was the first time I'd eaten there and it was good enough for me to make a second reservation for my birthday (albeit on the cheaper, pre-theatre menu which was really good value for money). I believe we paid £20 for 3 courses for dinner, which, to be fair, was the same price as the pre-theatre menu so it might be a bit cheaty of them. Service was great - unfortunately when we went back for my birthday, the waiters just ignored us all night. It felt like we were treated as lower-class citizens just because we didn't order alcohol and ordered from a pre-theatre menu, so keep that in mind.
Lastly we went to One-O-One in Knightsbridge, which is an expensive seafood restaurant. I think it was £30 for 3 courses? The food was brilliant - delicate plating, seafood was cooked perfectly, service was exemplary, and the only negative thing I have to say about it is the atmosphere. It's a little bit stuffy and consequently, quite pricey.
Unfortunately, looking at the list of restaurants, it doesn't inspire. I think in general, instead of actively looking for a good deal for a meal, I'd look for specific restaurants you'd like to try and see if they offer a LRF menu. It's a bit hit-and-miss.
Thanks for the feedback.
I am also trying to find other links as to which places are going to be involved, either officially or just setting up "street tastings", or walk-ins --without reservations. This way if we are in an area where there is some activity, we will have had an opportunity to either steer in that direction or pre-plan to do it.
BTW- Could you please let me know what the initials "LRF" refer to. Thanks again.