Agent for VMWare Backup Speed

what kind of speed are you getting from your agent for vmware backup?

Backup Exec Server 2012 sp3 is Windows 2008 R2 64 bit with 1 GB Link

Vmware is 5.0 Latest update with 1 GB managemnt link

using NBD without any GRT -  seeing speeds of about 2000-2500MB/min

is anyone getting better than this? 

anyone seeing much better than this? does 10GB ethernet make a big difference in this setup?

should i be doing SAN transport mode?

thanks

gd