As for breakfast, why are they exempted? Feels completely random. I thought I saw a breakfast room on my way out -- we weren't interested anyways since we were taking breakfast in the OneWorld premium lounges in Terminal 3.
While saying I would prefer that they did serve a quick breakfast to World of Hyatt members, there is a substantial quality difference in food offerings at this and some other European HP's when compared to the average US HP.
They at least pretend to have a hotel-grade restaurant. Maybe they overstate it. You can decide for yourself. I don't claim to have eaten there enough to know. But it is many clicks above a standard US HP in terms of the room, menu, and effort.
Breakfast is the real full British buffet, which they are proud of and price accordingly (which is too high and too much food for me before crawling on an airplane). They serve three meals off menus daily. The chippy dinner I bought was good.