Well, they are mainly just different implementations of scsi devices. Both of them work well in a VM.
The main differences are that lsi logic is more modern and has more features, also tends to work a bit better on modern OS's.
Whereas the buslogic device works well with older OS's.
VI-Toolkit & scripts wiki at http://www.vi-toolkit.com
Here is another link discussing lsi and buslogic
www.phdvirtual.com, makers of esXpress