better gearFollow

It depends. For utility in PvP, it's better than T6. For utility in PvE, it is difficult to make any general statement which applies to all classes and all item slots. There are some S3 items which are very good in comparison to T gear for PvE use, and those typically fall somewhere around T4/T5 in suitability. In general, it's ok to wear a few pieces of S3 gear. More than a few and your mana pool shrinks and your MP/5 shrinks and that'll have an impact on your sustained damage output for long Boss encounters.