When looking to see if something is an upgrade, the best thing you can do is to sim it. Generally, item level prevails above all. Otherwise, below are some general guidelines.
Damage oriented: item level >> Haste > Crit > Mastery > Versatility
Defensive oriented: item level >> Haste >= Mastery > Crit > Versatility
Haste has been and is an important secondary stat for Protection Paladin. It lowers the cooldown on most of our important abilities which results in greater holy power generation and thus more DPS and survivability.
Mastery is Protection’s best defensive secondary stat. The increase in block chance, flat damage reduction and chance to reduce the damage of harmful periodic effects while in Consecration make it an incredibly potent defensive stat, provided you are in Consecration. Damage-wise it’s still a very good stat giving a flat percent attack power.
Critical Strike is the least defensive secondary for Protection, but it’s still very good. Crit increases parry, which is nice defensively. This increase in parry also increases the chance of getting Grand Crusader procs, which results in more holy power from Judgement, and uses of Avenger’s Shield. Damage-wise Crit is obviously good. Big number do good dam.
Versatility is weird for Protection Paladin. Percent for percent, Vers is worse than Mastery defensively, provided you are in Consecration. Damage wise, it’s slightly better than Mastery. Does this mean you avoid Versatility? Of course not. You take whatever stats you can get.
Race doesn’t really matter for Protection Paladin, play whichever one you like more!
Blood Elf: Arcane Torrent is nice to have as Paladin’s don’t have a way to purge.
Lightforged Draenei: Light's Judgment is a very strong on demand AoE DPS cooldown and it deals Holy Damage which protection paladins can increase.
Dwarf / Dark iron: Stoneform / Fireblood is very nice to remove nasty debuffs you may be afflicted with. (Dwarf Only) Might of the Mountain, identical to Tauren’s Brawn, makes your critical strikes deal 2% more damage and healing.
Human: The Human Spirit is just a nice boost to all your secondary stats.
Cloak: Homebound Speed
Chest: Waking Stats
Bracers: Devotion of Speed
Boots: Plainsrunner’s Breeze
Legs: Frosted Armor Kit
Rings: Devotion of Haste
Sims will tell you which gems are best. You want at least 1 of the Fierce Diamond gems for the primary stat (example: Fierce Illimitited Diamond), otherwise haste or mastery gems will be best.
Phails: Phial of Glacial Fury for AoE damage, Phial of the Eye in the Storm as a slightly less damaging, but more defensive AoE option. Phial of Static Empowerment for raid encounters with relatively low movement, Phial of Elemental Chaos otherwise.
Healthpots: Refreshing Healing Potion
Weapon Oil: Primal Whetstones
Runes: Draconic Augment Rune