The unbiased answer will be: It depends.
P22 is hammer fired with manual safety, P99 is striker with passive safeties so the only real similarities are the grip and styling.
P99 comes AS (DA/SA with long SA on reload) or QA (similar to Glock, but with decocker, heavier pull, and a consistent takeup that will be gritty when new, but smooths nicely when broken in)
XD only comes SAO
Glock only comes Glock Safe Action
Aside from superior ergonomics, the biggest advantage of the P99 will be the decocker that will allow you to field strip without pulling the trigger. P99 AS has the best SA trigger, but will have an initial DA pull. However, P99 has worst aftermarket support (accessories, few armorers) so you better like it out of the box.
The Glock has the most extensive aftermarket support, a mushy trigger, a notoriously thick grip and if later than Gen 2, widely spaced finger grooves that can be uncomfortable to some.
The XD has no finger grooves and is more suitable for a wider variety of hands than Glock, but is not as nice a grip as P99. XD trigger has more consistent takeup than Glock (not mushy).