In my opinion... yes and no. There are certainly moments on the show that'll make you roll your eyes, but just as many that'll make you desperately fumble for the next DVD because you HAVE TO WATCH THE NEXT EPISODE RIGHT THE FUCK NOW.
I'd also say the characters are about as 50/50. I can't stand Jack, the ostensible protagonist of the show. I go back and forth on Locke, who has developed into the antagonist. (Maybe. Sort of. It's complicated.) I dither about equally on Sawyer, who I only developed some affection for in season 5. I like Sayid, I love Hurley, and I love Ben. And I think the first season episodes about Sun and Jin are some of the high points of the show. (Both in characterization and storytelling.)
Can't stand Charlie, don't care about Claire, go back and forth on Desmond...
Yeah. There are a lot of characters and a lot of plots going on all at once. It gets annoying, and it gets awesome. It's so scattershot that you will like something, and something will annoy you.