I'd say worth it. It isn't a bad series and has a reputation of being a very nice romance anime to watch.
In terms of plot and dialogue, melodies is a humungous step forward from memories. It's far more emotional and haunting, if you want to view it that way. It's like not watching ~Afterstory~ since the first season of CLANNAD had more comedy than romance in comparison to its sequel; it's the type of sequel that you don't expect to be good, but in reality is very very good.
Well if you ask me, Shaft did brilliant work on the visuals, but I found the story and dialogue to be a bit clichéd and this one voice actress really bothered me. If you want a good romance, I suppose you can't go wrong.
I don't think I'll watch the sequel to it any time soon though.
ef- a tale of melodies comes after memories, be sure to watch that aswell, cause it explains a lot of things.
Also, why would anyone hate you for Clannad? I think it was pretty decent.