You see. Simmen has got lvl 5 structure which produces a lot of metal. But maybe his alliance has lots of metal mines hanging round.

Hardly.

It's most effective at the beginning of the round. At that time you can build important structures before the rest of the world and secure a huge advantage. Later in the game, there is much need for large sums of metal besides building units and with the overhead system it can only be used to build a small army from scratch and hardly does anything for someone with a big army.

I find the worker and production boosts are the most advantageous once a round is established and neither of these are game breaking, they just give a slight edge which should be gained if you're spending real money.

Lol you must have a lot of workers . I'm rank 23 on F1. I was rank 20 at one point (yay my first achievement!). I don't support either. All it takes is a good alliance and skill (well i wasn't always in this alliance, used to be in a loner, then a decent alliance).