Evergrey have a few distinct eras in their discography, not unlike Maiden in a sense.
They started out as a progressive metal band, heavily inspired by Dream Theater, but with much more straightforward arrangements. Their early identity settled into a quite dark and progressive power metal, something they followed for their first 5 or so albums. Their lyrics tend to deal with emotions, mental health and stuff like that, but they also have a concept album about a person who got abducted by aliens, or one dealing with abuse in the church. I think the best way to get into them is their first live album, released in support of their fifth release (so in a sense their
Live After Death, which funnily enough gets referenced towards the end). Great performances, phenomenal setlist and they got a couple of guest singers to really bring the powerful choruses to life, as well as a string section for some songs.
After that came their experimental phase, where their sound became a bit more modern, they started losing some of the classic members and basically went through their darkest era. It came to a point where their 2011 album (Glorious Collision) almost would've been the final album and Tom S Englund, the singer, guitarist, lyricist and band leader, was ready to give up.
Then, the guitarist and drummer who were on the live album returned and they've stayed with the same line up for over 10 years at this point. They've found a new creative spark, have seen a lot of success and released a string of great albums, that stylistically are quite similar and are a mix of melodic and modern metal. They tend to use 7 or even 8 string guitars, double bass drums, but the vocals are always clean (except for like 3 or so shouts spread out over the entirety of the discography used for effect). The previously mentioned
The Atlantic is the middle one of those albums and personally my favorite of them. There is a lot of great music on there. A lot of it is mid-tempo and they are known for writing interesting ballads. If you enjoy the vocals you'll probably find something to enjoy on there.
Btw, they are Swedes and I think every single album has at least one tiny grammatical error (Stuff like "
Her lips doesn't move" lol) which is kinda endearing to be honest.