As I've already said, I was comparing the two while trying to decide. No NAT figures there, only routred/bridged config with and without conntrack, which is not the same. Actually, far from it. The 450G is capable of a NAT througput at around 200 Mbps (based on others and on my own experience), while, in theory it can route traffic at near gigabit speeds without NAT.
RB2011L-IN will do it have nice price (use them like manageable switch traffic >200Mbit)
RB1200 not wort the money better bay some PC
RB2011L-IN have 10 ether ports 450G 5 ether and 256Mb RAM (u need RAM if u use Queues, Queue Tree etc..)