The Line2x(bob) and Line3x(Laced) modes in 240p PS2 game are totally impressive and awesome, but the modes are not effective in 480i PS2 games.
These are deinterlacing modes and only affect 480i/576i content.
I would say that the passthrough in 480i and display deintereracing is the best quality. Could you recommend better option in 480i resolution? I really love the 240p & Line3x mode.
If your priority is low input lag, use the OSSCs deinterlacing modes. If your priority is picture quality, use the passthrough function and let your TV, or secondary processor do the deinterlacing.