TBC ret or shadowpriest

My main on fresh is a paladin.

I now leveled a priest with the mindset to heal on that aswell, however my guild wanted me to go spriest, because we have alot of warlocks, and i thoguht why not, lets just do something different.

And i just love spriest, goddamn its fun and my damage is decent.

Now my plan was to go ret in TBC, but i never played ret in TBC.

Now im strongly thinking of going SP instead tbh.

Can you guys help me? what are the pros and cons of ret? i like the idea of twisting, but it also seems very punishing.

SP brings great ultility, but it does seem to fall of in damage alot later in the expansion? where as ret seems to actaully be able to be in top spots.

What about pvp?
This will be a huge factor for me, i know both speccs arent top speccs, thats ok for me, i dont need to play meta.

But which is more versatile? im also afraid of getting trained a bit too hard as SP, which seems to be the reality.

Can you guys come with advice?