Master page feature will be very useful, in Adobe Fireworks master page feature is good example.
Also option to share layer (group of layers) to multiple art-boards will be very useful.
For example you are using cart widget on several art-boards, and ability to share same layer (cart widget) on all of them (including positioning top-left from art-board) will save lot of time when editing. This is not same as symbols because here you share also positioning of layers. In ideal situation you create symbol "cart widget" place on art-board, position where you like to appear, and than share that layer across multiple art-boards. Latter on when you need to change/adjust position you can do that from one place.
Master page feature will be very useful, in Adobe Fireworks master page feature is good example.
Also option to share layer (group of layers) to multiple art-boards will be very useful.
For example you are using cart widget on several art-boards, and ability to share same layer (cart widget) on all of them (including positioning top-left from art-board) will save lot of time when editing. This is not same as symbols because here you share also positioning of layers. In ideal situation you create symbol "cart widget" place on art-board, position where you like to appear, and than share that layer across multiple art-boards. Latter on when you need to change/adjust position you can do that from one place.