OV Innovations is developing a conversion kit that will allow end-users to mount FILBE shoulder harness to ALICE frames. This would certainly be an upgrade over the standard shoulder straps and FILBE straps are quite affordable ($10-20) compared to many aftermarket pad kits. Additionally, the plastic frame sheets that have replaced the ALICE frame have a reputation for breaking so this could be a solution.
This kit is still in development. Keep your eye on OVInnovations.com for updates.