I've played one from 1st to 11th level in a tabletop Kingmaker campaign.
Is there anything specific you would like to know?
I played as one and it was great esp if you know who to be the deity and domains ie taking Plant domain works great in a forest or plains area.
I love the class and have been trying to get someone in my group to play one for ages. The player who currently runs our cleric would actually benefit more from the priest because she actively avoids combat as much as possible and channels energy like a boss. I've not given up on my quest. I'd let her convert her cleric over to a priest if she wanted to.
Domains: Luck, Travel(Trade) and Knowledge(Memory).
The party has gone through several incarnations as players have joined and left and, as a result, my Priestess has had to fill different roles at different times and she's more than held her own: she's the most perceptive in the party, the best tracker, not too far behind the Sorceror in the social skills (courtesy of the Trade domain power) and can roll on any knowledge skill asked for, due to the Lore ability; 2 ranks in each knowledge skill means there's not a lot she doesn't know.
She also has ranks in various other skills, including heal, fly, appraise, stealth, UMD and a couple of professions, to represent the fluff.
Her only flaw is that she is very squishy (44hp and an AC of 18 at level 11) and so needs to always have an out. To this end, she has a ring of invisibility, a ring of Freedom of Movement and she uses a MM Rod of Extend with Overland Flight to keep her out of harm's way.
Her combat role is to stay behind the melee characters and buff as required, including using her "Touch of Luck" domain power; fly and DD to get them to hard-to-reach opponents; Protection from/Resist Energy, Invisibilty Purge, FoM and similar spells, as and when required. I've not rolled an attack die since level 4!! :)
In short: set up properly, they can turn their hand to anything, and this is before any of their numerous spells are cast.
(Start/current stats: Str10 Dex14/16 Con10 Int14 Wis16/22 Cha14)
As a DM, I'd allow one in a game but I'd reduce the Fort save to a slow progression. Given the academic leanings of the class, it makes no sense to be on a fast progression as it is now.