S4 ended w/ well S5

I watched S1, S2, and S4. S1 is still my favorite.

S3 not available on Viki or Netflix so can't watch it. It's not that the acting wasn't great because despite the ML changing, each MLs were excellent.
The English actors weren't great though. They sounded like they were reading a script just memorized.
S4 story wasn't strong, rather it felt unnecessary grotesque. I was distracted by the bad wig many episodes.
FL: There's utterly no character development on her part. How she started acting is how she ended.

My favorite part is actually the supporting role of Shim Dae Shik (Golden time detective that was in S1) who came back. I loved his character. There's depth and complexity in his acting which is much more memorable to me than the FL. If you watched him in While you were sleeping, you'll just love his acting all that much more.

If they move on to S5 I'll still feel pot committed to watch it, but I won't expect much either.