Everything about it. The Eric Johnson Stratocaster is the best Stratocaster I've ever played. Hands down. The 2nd best trails so far behind as to be out of sight of this front runner. Combine the very best of a vintage Stratocaster with a modern fretboard radius and a custom designed headstock / neck volute / staggered tuner height requiring no string trees and a steel bridge block painted silver that feels extremely heavy when pulled from the guitar body. Low output AlNiCo III pickups in the neck and middle position for an extremely vintage tone yet sporting an AlNiCo V in the bridge position to pump those gainy solos out. The EJ is the best combination of a vintage '57 Stratocaster, a modern players requirements and input from someone who has played the Stratocaster to it's limits.
None. Zero.
Note* I tend to be very picky. Nothing's ever perfect. Except the EJ Stratocaster.
Of all of the amps, guitars, pedals, recording gear, etc. that I've purchased and played over better than 50 years, the Eric Johnson Stratocaster is simply the best piece of gear I've ever owned. It is without competition. Nothing comes close.