I’m with “wpeople”. Traffic and CPU load caused by BGP updates are more important. The main question I would ask is: Is this router able to handle two full feeds when they are flapping or something. This situation can bring a nice running system (under normal conditions) to it’s knees.
Its a bit late in the day, but we have customers running RB1000’s with two full BGP tables, although they did get a memory upgrade to 1gig.
They work fine. Re-convergence is fine although if you have a flappy link the CPU maxes out. However BGP flap dampening should be configured (IMO) in this case to calm this until the link returns to usable.
Can’t speak directly for your box, but hope that helps…