BGP evaluation

Hi, In general, how is a BGP implementation evaluated/benchmarked by an operator? Are there any well-known figures relating to memory-consumption, speed of convergence, scalability etc. that one can benchmark with? There was a write-up on Data Comm magazine testing Juniper's M40 BGP. I haven't seen much more than that - especially test procedures used to compare various vendor implementations. Thanks in advance, -Sathya