Diablo 2 added alot for gameplay, yes. But I dont think the above ground free roam thing worked for it at all...I much preffered the dungeon crawling of D1...it made it much easier and more efficient to level, and added a nice claustrophobic feel to it. Yeah, the projectiles didnt shoot far, but you had speed on them, and that little distance does help (I just finished playing through as a rogue with only bow and arrow as my weapon).
While D2 is still awesome, I still cant play through it all without getting bored. Not so with D1 which I can do over and over again and still have fun with.