i have a 507 and it sounds really good for an entry level kit but 2005 is much better since the wood is birch(as mentioned). it would sound more awesome than 507, especially the bass drum. punching power talaga.
what i hate about the 507 is the bass drum, i can't seem to find the punch i'm looking for. ndi ko sya matimpla ng maayus.
what i don't like with 2005 is yung sizes nya, personal preference. it's too big for me.
good luck with your new kit. Sonor is a very good brand.