Turns out the Small Form-Factor Pluggable Gigabit Interface Converter (SFP GBIC) has a vey limited number of insertions in and out of a chassis. A range of 100 to 500 is specified for older GBICs but for newer types the lifetime rating for insertions on the Nexus 7000 is between 150 and 200 cycles (of insertion).
Has a big impact on using modules in lab and testing environments especially where things might be changed very often. 150 insertions for a GBIC is not that many lab setups.
Molex Connector Production Specifications for Small Form-factor Pluggable (SFP) Stacked 2-by-6 Multi-Port Connector with 4 Lightpipes, with Press-fit PC Tails, 240 Circuits – These are typical examples of the connectors used in the manufacture of switch modules for just about every networking vendor.
Durability (mating cycles max) 200