It's been a while since I've played. Most people went with mage armor to use meditation. No one used plate armor for anything.
Has that changed? Is plate armor worth using again?
Yes, it has changed, plate is much more usable than it used to be. All non medable armor now offers stamina protection, and inherent lower mana cost on up to 5 pieces which can break the property cap. Medium armor like Studded, Ring, Chain, and Bone have moderate stamina protection and 3% LMC per piece. Heavy armor like Plate and Stone have high level of stamina protection, and 1% LMC per piece.
Personally I find the stamina protection level of the medium armors to be good enough that I no longer need leech stamina on my weapons (especially with divine fury) and 55% LMC is really nice. So personally I think you are best off with Studded armor.
But plate is much more functional than it once was.
Just don't bring up refinement.