Thanks for you attention Andi. My favourite option, so far, is dropD (like standard but with the 6th string tuned down). This gets the best of both worlds: basically you keep the standard tuning chord shapes that many of you have mentioned on this thread, BUT use a flat barre for the power chords (much to Roy's taste). I think this option makes sense with most of what has been written here. I'll probably give it a go one of these days. Just have to work out the correct voicing for the chords. Cheers! Joao