You can design your network with the future in mind and then grow into your topology. That is not possible in today's IPv4 world where everybody is concerned with not wasting addresses.
I think it's worth clarifying that RIPE's IPv4 policy specifically states that one-to-one renumbering for valid assignments are fine.
I understand that. But in the IPv6 world, if I have a plan to build an organization in 20 countries with 3 regional manufacturing plants, and 35 sales offices, I can build the network topology around that plan, even though I only have 8 employees on the second floor of a former typewriter repair shop. I can size my subnets according to my 10-year plan and my ISP will give me the /48 that I need to make it that way. However, in IPv4 my ISP will not accept the 10-year plan and will not give me 6,000 IPv4 addresses for my factory subnet that currently contains only one server. There is a clear philosophical difference between IPv6 addressing and IPv4 addressing. --Michael Dillon --Michael Dillon