SAP Self Service-anyone have opinions, ideas or success stories to share?

I'm working with an organisation that currently has had SAP Self Service ESS/MSS functionality in place for some time however it's highly customised, not multi-language and the portal needs upgrading. 

They are looking at how to tackle the next evolution (on a global scale) for self service within their organisation..  questions arise such as the role of the Manager vs HR or Admin (i.e. should self service be transactional or purely informative), how do you manage multi-lingual capability and how can you make it user friendly without customising it within an inch of it's life - anyone have opinions, ideas or success stories to share?