Both calibers are respectible performers and very capable hunting rounds. However, in every category you mention, the Swede gets the nod. It shoots bullets at a flatter trajectory that have better BCs and sectional density than the 7.62. For any given bullet construction and weight, the long, slender 6.5 bullet is going to outpenetrate and outperform its 7.62 counterpart. The Swede is a very mild round to shoot, and can be loaded with bullets from 85 gr up to 160 gr for a broad range of uses. Its terminal performance, bullet weights being equal, is second to none.
I have read that the 6.5x55 is one of the best engineered cartridges going in terms of internal ballistics. I believe, "it is one of the few calibers that simply cannot be improved upon," was a quote that sticks in my mind from a ballistics expert (don't remember the source). From what I have seen in practice, it is an outstanding caliber. It is accurate, reliable, an unbelievable performer on game, and a pure joy to shoot. Have fun with it! :grin: