I made a study on 8 different Metal gen BeyBlades. I compiled their weight, type and stats and then measured their endurance and nature.
The BeyBlades studied:
>Gravity Destroyer
>Thunder Leone
>Phantom Orion
>Big Bang Pegasis
>Galaxy Pegasus
>Thermal Lacerta
>Burn Fireblaze
>Twisted Tempo

An average of 15 spins was used for each blade.
Generally speaking, the stamina statistic correlates somewhat on endurance, while the performance tip seems to be the obvious answer to a good stamina build as agreed upon the meta-game.
I will post figures further in the thread.