What bothers me about the tyre thing is that it's completely dependant on what Pirelli do how teams fortune's go. So mercedes are being heavy on their tyres, therefore they have relied on Pirelli making their tyres at least somewhat durable. Ferrari and Lotus seemingly the other way but Pirelli, who appear to be just playing this by ear a little too much could have quite easily made a tyre more durable than they meant too for teh Spanish grand prix and this would have favoured Red Bull and Mercedes, nobody has actual time to prepare and they just seem to be some sort of lottery of design your car a certain way and hope Pirelli makes tyres that favour your design. It's stupid.
I'd much rather than they limit the amount fuel they can use, at least that would be tactical and encourage some form of coherent technology advance.