W.salaam.
It depends upon what kind of model you are working with. If you are working with a simple 2-Way Slab Beam System, automesh would be the best to go. If your model is very complicated then you have to see what kind of mesh elements you need.
Here is a list of all the new updates to ETABS. The page says that ETABS 2013 has "Enhanced Meshing Capabilities with More User Control"
https://www.csiamerica.com/products/etabs/news
You can also check out the following link that discusses all the new features including updates to meshing in detail:
http://www.csiamerica.com/products/etabs/features
Thanks.