CIPsoft made drastic balance changes in 7.8 with the introduction of rune hotkeys. From a practical perspective, it could be seen as less drastic if we include cheats like aimbot in the accepted meta, but when revisiting old versions of Tibia in OT servers I don't think it's helpful. Why would you play 7.6 if you want rune hotkeys? So as far as CIPsoft's tibia servers go, the 7.6 balance only lasted for one year.I don't know what ots you played. Ot servers have whatever their owners set.
But you said that what you called the "true 7.6 mage formula" cipsoft too had used for one year only. While those spell costs set in 7.6 update were in use for many years. And for some spells like exura vita for instance - still are.
Open tibia is a different story. They are not limited to the short scope of CIPsofts versions, but it's up to the owner to implement their own balance. From my experience the oldschool OT community implemented their own custom version of 7.6, which has stuck around and become the "true 7.6 balance", even though it differs from CIPsofts 7.6 balance.
CIPsoft intended mages to use more instant spells, so they made mana fluids more efficient and increased regeneration, generally by a factor of 4. They didn't use the same factor for instant healing spells though. The most important healing spell Exura Vita only became more efficient by a factor of 2. That's not true for most OT servers though.
So what happens when you give Sorcerers and Paladins Exura Vita for 80 mana?
- Druids lose identity
- Self-healing with Exura Sio (70 mana) is not that much more efficient than Exura Vita (80 mana).
- Knights lose identity
- Paladins are intended to be stronger healers, but spending 160 mana to heal will drain your mana. You can spend 80 mana indefinitely by using mana fluids.