I've been debating for a few days which I want to level as an alt, and searching the threads here I only really found one entry by @Stfuppercut in a thread about least gear dependent classes. I have never played either class in vanilla, but I enjoyed them both in retail during various expansions. I'm would mainly be playing the class for pvp, specifically wpvp and pug battlegrounds (I'm just making an alt to have some fun on). I likely won't be raiding with this toon, so that will not be much of a factor. Just looking for some insight from people who've actually played the classes in vanilla about what makes each fun/unfun to play mainly.
Also at one time posts like this were like 30% of all new posts here and I'm waxing nostalgic for the posts of 2 months ago.
Raikan - Night Elf Druid
Keatts- Human Rogue
Grobbulus - US
So if you are looking for 1vX situations, warlock is better especially as the game progresses.
If you are looking for 1v1 situations, spriest is significantly better until around tier 2, where warlocks start to bloom.
A late game SL warlock will demolish most players in a 1v1 and will outperform spriests in most 1v1 situations.
Shadow is pretty bad in group pvp situations, they simply oom too fast. Especially if the enemy team is pressuring with viper stings.
Spriest is a meme. Warlock has a ton of great builds and a lot of different ways to play in both PvE and PvP.
Spriest is more of a 1 trick pony that can be VERY dominant in 1v1 situations.
I agree with Uppercut here, Warlocks scale very well with gear coming in later stages of the game. However they also have a different playstyle then Spriest.
Ten Storms EU Alliance
Finnigan - Dwarf Hunter Lvl 30
Portalmaster - Gnome Mage Lvl 19
Shaelur - Dwarf Paladin Lvl 22
Shaelus - Night Elf Druid Lvl 50
As a priest you still have the option to go disc healer for group PvP. You'll be welcome in most bg groups.
If you want to purely do damage, I'd recommend going warlock. It's a much more versatile class. Although, gameplay between spriest and warlock isn't too different (dot, fear, run, repeat).
I would prefer to play warlock, the game is similar to Priest but have some different dimension and excitements.
If you hate healing, don't touch Priest. You don't want to be that dude who fancies himself some kind of snowflake and wants to be taken seriously as a damage dealer. I've met very few of them and they weren't raiding and all my guildies just kicked them for many reasons I'm not going to list here.
That being said, you have a lot more viability, damage, utility and pvp opportunities as a warlock simply because you're comparing 4 viable specs at least (2 for dps and 2 for pvp) against one that does a niche thing that's going to be super irrelevant for another few phases.
Yeah you melt faces 1vs1 but by that metric you might as well say warriors suck because they can't beat mages 1vs1.
Spriests are nice (one of the best specs in the game actually) in 1v1 but geared Soul Link Warlocks are a whole new level of insane. And Warlocks are just way better DPSers in group PvP. Priests can have a massive impact in group PvP but as a healer, not as a DPS. Warlocks are pretty insane in BGs. The only two downsides I can think of with Warlocks in BGs are that Mages do better at AoEing and that they are so gear dependent. This video is pretty representative of a geared Warlock in BG: https://www.youtube.com/watch?v=dOmXT3cxz0Y (the guy has great Warlock videos overall).
I'm not touching alts anytime soon, but Priest vs. Warlock was under consideration and I'm firmly in the Warlock camp now.
I'm already doing enough healing as a Holy Paladin.