Eternal Sharp features a free-spinning tip attached to a metal shaft which is held by the Bottom. It's gimmick is meant to reduce surface friction against the stadium, therefore increasing stamina.
The part was one of the most heavily anticipated parts in the MFB lineup when first announced, but ES is actually a huge disappoinment in terms of performance.
Firstly, ES lacks a metal bearing, which would significantly reduce the friction between the free-spinning tip and the rest of the Bottom. All of the best free-spinning tips, notably Bearing Core, had NSK Shield Bearings which allowed unhindered spin.
Secondly, the tip shape of ES is not conducive to optimum Stamina; the sharp nature of the Bottom means it is easily destabilized. As all Sharp tips do, Eternal Sharp also has trouble regaining balance, hence making this a poor choice for Stamina. That said, ES still remains superior to BS and S as Stamina Bottoms.
This is a good tip for Starters/ Beginners who would like to focus on Stamina, but don't have top tier parts like WD, EWD, SD, and PD. In the anime, ES has been shown to be able to create sonic waves and regain balance though it is not true in real life. Depending on your angle of launch, ES has been shown moving at the speed of an SF bottom and also with barely movement at all. ES also gives the bey the ability to tilt at an extremely low level (the Fusion wheel is about 8mm) without floor scrapes. This gives it a huge advantage when destablized or when facing attack types. It is also and exceptionally high bottom, changing a 125 spin track height user's height to that of a 145 track. It is outclassed by EWD, WD, AS, and B:D.
The height of this bottom is also shown to be pretty useful on Flame Libra T125ES as it causes the bey to jump and somehow lowers the attack impact when hit directly.
Flame Libra does still have an advantage to win when it's down low, if it doesn't grind on the stadium floor. Libra can knock down the other beyblade to make them lower as well.