Is there any difference among the following three methods for establishing a static route?
From ICND2 OCG:
Example 22-2 Static IPv6 Routes: Three Options
! The next command uses R1's S0/0/1 as the outgoing interface
ipv6 route 2001:db8:1111:3::/64 S0/0/1
You should only use this option with point-to-point links. For ethernet, it may not work correctly (i have to think about it to decide, under which circumstances it may work) ...
! The next command uses R2's address as the next-hop router unicast address
ipv6 route 2001:db8:1111:3::/64 2001:DB8:1111:2::2
Possible but unusual. The usual case is to set the route to the link-local address of the gateway (which requires to specify the egress interface also, because link local addreses have only to be uniq within the same link).
! The next command uses R1's S0/0/1 as the outgoing interface, and
! R2's link-local address as the next-hop router address
ipv6 route 2001:db8:1111:3::/64 S0/0/1 FE80::FF:FE00:2
I think, this should be seen as preferred way to configure static routes.