my money ' s on India to grow the first mushroom cloud <| sep |> I think you have a pretty good route overall . My suggestions are to consider adding London to the beginning of your trip before Paris , and Madrid to the end after Barcelona . I would also drop Zurich and replace it with Munich and Innsbruck , which I think are much more interesting cities , and are better connected to Vienna and Venice . Finally , I think Copenhagen seems kinda out of the way and shoehorned into the itinerary , so I would consider dropping it . <| sep |> I personally don ' t have the m 12 fuel but our shop has three . I love them . The battery life is fantastic for what use it for . There ' s a ton of power . Maybe it ' s because they ' re newer but they feel super solid . The hammer drill function has saved us a couple times . The 18 v fuel is also awesome . It ' s way more power than I typically need . It is quite heavy but the thing is a monster and lasts a long time . I primarily keep it just as an excuse to carry an 18 v battery around . I use a Portaband and jigsaw quite a bit . Edit kind of misread your question . Anyways , they ' re comparable . An 18 v system will be more powerful but the fuel comes close . Plus the motors themselves will last longer . They ' re definitely worth the extra money if use a drill or impact frequently .