Onelove The amount of mana you're getting back from the Reclaim system in its current state is actually less than what you could get from the Execute system.
Right now, at 60, Reclaim gives you 25 mana per stack. At 5 stacks, that's 125 mana. However, you need to spend mana casting spells to build those stacks in the first place.
Exceptional Fire Volley, for example, gets you to 5 stacks at the cost of 60 mana. So you're effectively gaining 65 mana every 30 seconds.
Compare that to the Execute system, which could refund the entire cost of a spell—and potentially up to 3x the cost if you got multiple kills with an AoE spell. From what I remember, Flames of Eth cost somewhere around 300–400 mana. Even a partial Execute refund could easily outpace what we're getting from Reclaim.
Now, the numbers can obviously be adjusted, so I don't think that's the real issue.
The bigger problem is the type of playstyle Reclaim encourages. You're directly incentivized to keep your target ALIVE as long as possible to maximize your mana regeneration.
For example, say you're soloing and have 5 stacks on a mob that's at 5% HP, but Reclaim is still on cooldown. If you want to maximize your mana return, the optimal play is to stop attacking, sit there, and stare at the rooted mob while you wait for Reclaim to come off cooldown.
The same problem happens in groups. Your party can burst down a mob with 5 stacks when Reclaim is only a few seconds away from coming off cooldown, causing you to lose the mana you spent time setting up. On top of that, other Wizards can Reclaim marks that you applied yourself.
That's what feels off to me. For a DPS class that's supposed to be nuking monsters, the mana-recovery mechanic shouldn't encourage you to slow down your damage, or delay kills.
The older Execute system did the opposite: it rewarded you for killing your target with precision.
