It was me (and I am female) who paid just short of £40 for the two breakfasts.
After getting over the shock of how much a breakfast was (we did know before we went in as we had read the menu) and after all it was my birthday that day we decided for a little treat.
The quality of all the foods in the breakfast was fantastic, from things like the proper butter, the Bonne Maman (sp) marmalade, the taste of the mushrooms, the nice golden yolk of the egg. The quality of the meat in the sausage, bacon etc was excellent and we thoroughly enjoyed it.
The floor was covered in c**p when we returned for a second visit for a lunch probably the following year.
Would we go back? Difficult question to answer that. Would need to know what the other alternatives are in T5. Don't really go through LHR much now as BA have ridiculous prices so as we live near ABZ tend to use KLM via AMS.