Does it make sense to use Automapper if source and destination properties(names) are totally different.

Hi Techies - 
I have two questions for Automapper :
1. Does it make sense to use Automapper if source and destination properties(names) are totally different.
See they are same from human reliability perspective like
sls_order_no ==> SalesOrderNumber tran_di ==> TransactionIdentifier
above both properties are same when some one reads but for Automapper they are different. Now suppose i have lot of complex class (nested) with similar property naming conventions where they are same for human readability but not for Automapper.
I am not sure in this situation i should be using Automapper or should go for traditional style, specially considering performance of Automapper is little poor then Traditional style.
2. How to use Automapper in Class library like where to keep all mapping setting (Mapper.CreateMap) code. 
Any help would be much appreciated.