While I do agree that 5th edition seems like it might be a bit easier to work with (going off of the playtesting packets and a brief scan of the player's handbook) I wouldn't say that it is better than 3.5. it is certainly new and exciting, but if you have already developed content for a 3.5 setting, then you should stick to it.
Also, if it pleases your fancies, you might want to look into publishing the final product in the Dungeon Magazine! This is something that I suspect would be a big hit in the D&D community.
Looking forward to seeing it!