I’m not sure what you were expecting. Fast eMMC and below average SSD’s don’t have a world of difference between them in terms of perceived speed. Booting is also not solely based on disk performance, but also heavily dependent on the CPU – which is of course relatively slow. You will probably only see a small boost in performance on really disk-heavy tasks.
On the other hand it’s quite possible that the keyboard issue also has an impact on the performance, because my V3 has much slower eMMC but faster boot times.