IPv6 has massively simpler routing requirements then IPv6. Any core router will be able to handle the routing for the entire IPv6 routing space with a total of 4000 routes. Nowadays IPv4 requires 36000 or more.
The address space is also designed to be able to handled efficiently by 16 bit processors. The idea being, of course, that you would have most every electronic computer-controlled device with some sort of IPv6 support.
If anything IPv6 should provide a boost in performance over IPv4. It's just much more efficient since network addressing is much better designed.