^
For what it's worth, I say that you should definitely wait until you've finished the series before you watch the "Paradise Lost" movie. Like most KR movies, the story that's used in the movie is not really part of the canon used for the series, so it's not like you'd be missing out on anything or messing anything up by not watching it once you've made it up to a certain part of the story. If anything, finishing the show first will make certain elements in the movie less "WTF" when you see them.
Faiz is definitely one of the more serious/darker series to be put out, though it does have it's lighter moments now and then. Personally, I found a lot more complexity in some of the secondary characters compared to Takumi/555. When I was watching it, I found myself empathisizing/getting "emotionally invested" in many of them and not really caring that much about what Takumi was going through (the fact that Handa's acting can be rather wooden at times didn't help matters in that sense). Without giving too much away, near the end of the series is one of the better "OMG that is SO not fair" moments in Kamen Rider, IMO.
Oh, and Smart Lady is such a weird mix of "nuckin' futs" and mysteriously hot.
Haga Yuria (who played Sonoda Mari in the series) was only 15/16 when it was made, so yeah...not perv-able at the time.
EDIT: Fortunately she's legal-age now...so yeah...she's damn sexay.
http://forum.jphip.com/index.php?topic=19645.msg581116