S60 vs ST60

Hard to say until they are reviewed, only reference would be last years u50 compared to st50, blacks were close but there was a pretty big gap in picture processing and light output. And the abl was much more aggressive on the u50. Perhaps this year will be different tho

Well, if the PQ is exactly the same and you're not interested in Smart/3D features, then I think it's an easy decision.

Edit: As chunon said, it will depend if the PQ is equally comparable or if there are significant differences.