LOL, attack away. I'm not the sensitive type. The first level of CoD was crap, but once you got past the castle's exterior it gets a bit more interesting. Also, the familiars (I forget what they call the things) really added to the experience for me. After you beat it, you can play through as Trevor. Pretty fun.
Incidentally, I thought that the level design was less developed in LoI with the central hub and teleporters. In CoD the whole castle was connected. Admittedly, both games had a lot of rooms that looked too much the same and need to work on including more curving structures. Anyway, I think they're getting there. The weapon and item customization was really upped in CoD.
Leaps and bounds ahead of C64. That game made me cry.

Played Eternal Daughter, didn't really like it that much, but I liked Derek Yus other game, Aquaria. Most of the metroidvanias I've played lately are freeware PC games, though. Knytt, Knytt Stories, Untitled Story, Lyle in Cube Sector Zero, Iji (not really a metroidvania, but close enough), Maze of Galious, and La Mulana. And Cave Story, of course, but that was a while ago.
Yeah, but it's not for PC or DS :(
Have you played Legacy of Darkness? It really was everything CV64 should have been.

Yep. Markedly better than CV64, but still wasn't a big fan, less because of the game itself than because I always felt like - "Well, why didn't you release this in the first place?". In retrospect, a decent enough game give the time period, but when I played through a bunch of levels recycled from CV64 I felt kind of ripped off at the time (I did pay for C64 and LoD at full retail). I still kind of feel like it's more of an expansion pack than a game. I never felt that way about any of the handhelds, and they all used the same engine, too (and often recycled enemy sprites).
I think recycling levels in a re-release less than a year after CV64 (even if they were changed up a tad) was lazy and disrespectful to the fans. That's the only time I ever felt slighted by Konami (which is my favorite console dev) besides maybe Silent Hill 4, which I later found wasn't even supposed to be a SH game (and boy was that obvious) and with the fact that you had to go through the same levels twice (once solo, once on an extremely tedious series of escort missions).
For a CV game, the controls on the N64 were still a little wonky and stuck in that pre-Devil May Cry Tomb Raider phase of action/platform games, too. The 64 bit Castlevania games were the main reason I gave up on action games until Devil May Cry.