Yeah, I may just have to go out and buy some UK baking powder to try out before I pass along any recipes. The ones I was asked for were for birthday cake and cupcakes - not something I make every day and when I do, I need it to come out right. So I was hoping to learn from other people's experiences. But I guess my family won't complain too much about having to eat another cake this week for the sake of experimentation!
I did find the info on flour very interesting. I have baked here a lot (all kinds of bread, muffins, cookies, cakes - all with US recipes and if needed with US baking powder) and never really noticed any difference. Although I've never been able to get my Tollhouse choc chip cookies to come out the same so I'm going to play with the flour ratio a bit now to see.