I had a Brandon 80 installed in December. I had an older range cooker before that which actually heated the kitchen, whereas I have to turn on the rad with the Stanley. I usally time the oven to come on before I come home so it's a bit warmer but it's not good enough to heat the room. I haven't really explored the whole oven element of things so maybe I'm just missing how to set the temperature.
I find it fantastic for hot water, never had it so hot or in such plentiful supply with my last cooker. Stanley man commissioning was excellent, told the plumber and electrician exactly what to do so I'd get the best out of the cooker. Have a theromstat on cylinder and the circulating pump had to be moved from where it was previously.
I do find it hard to keep clean (because of gloss). I think you can buy a special cleaner, which I will have to purchase. My last cooker was a standalone in the middle of the floor, whereas this one should be boxed in as it has a matt finish to the side and has 2 large bolts at either end, which also get very hot (in case you have kids).
I've cooked a few times in it and overall I have to say I love it. Timers are fantastic - you can set the oven, rads and/or water each to come on at three different times in the day. Stanley man recommended leaving it on 24 hours a day and just controlling it with thermostat but I'm out all day so it was pointless. I left it on all over christmas and I wouldn't think it used that much oil at all. I actually find it economical on oil. Got 1200 litres in September and I still have a half tank. The last cooker was reaching it's best before date and was guzzling oil this year so most of my consumption went on that. I have 11 rads and they are red hot with TRVs set to 3.5.
I looked vaguely at the Rayburn but the Stanley definitely looks nicer.