it turns that this should be a common feature for opencart admins, basically the operation team would like to see orders with priority shipping method and process those orders first. on 1.5, no way you can see this at once. basically the orders page looks like this by default
they actually want to see the UI like this, with shipping method on the overview
even more, they want a filter to see all orders with priority shipping selected.
To fix this, pretty straight forward. change the orders module/controller/template file, to include shippingmethod in the data query back. and add a filter logic to narrow down records.
I have a patch file, email me if you are interested. click about me on the page to get my email