The Dracula X Chronicles was the first and only Castlevania game I ever played, and it is still my most played game for the PSP.
I think this is a pretty awesome game, and even if I never get the chance to play another Castlevania I can do just fine with this only because it comes with both a classic game (Rondo of Blood original & remake) and a modern game (Symphony of the Night), both of which are considered the best of their individual styles.
I actually perfer the Rondo of Blood remake over the original for a bunch of different reasons. I love how Ayami Kojima uses her art style for the characters, giving them a more medieval oil painting look than that generic anime look of the original. I also perfer the remake Maria because she's treated more like a sympathetic heroine with her own background, where as in the original she seemed like a silly joke character intended for laughs.
But as far as being my first game in a series I had never played before, I love how it gives you the option to choose between a male or female character. It doesn't seem like many games these days let you do that anymore, usually there is just one playable protagonist who is one gender or the other. As for the fact that Maria is a playable female, it's kind of nice that for once the female hero is a little kid and not a sexed-up adult female. It's not that I have anything against sexy females, but having a female hero with no intentional sex appeal is an extreme rarity for video games. Plus I like how she parallels Richter by using summoned animal guardians in the place of "normal" vampire-killing weapons, and how she eats sweets to heal herself instead of meat.
As for Symphony of the Night, since this re-worked version seems to be the way the game was intended to be I'm happy I played it first. I kind of wish they changed the monster names to what they originally were in the Japanese version, some of the enemy names for the US version of the game are just silly and don't make sense. Like swapping the Devil with the Cthulu.