No one can judge how fast or slow an application will be on any given server but I can say our application runs on many many different server hosts and has extensive performance enhancements which i think puts it at the top of the pack coupled with the fact it is the only truly support script you have meantioned. Coppermine is known for its lack of support and its
vb integration is really non existent.
There are no gallery2 import scripts that I am aware of.