You are absolutely right my friend.
Your point is well taken, For me, and maybe others, having seen a previous version,did bias my opinion.
On the way to the movie with my friend, I tried to remind myself not to have great expectations, and to try to avoid the comparison making. But..,looks like it didn't work. I think it was the fantasy part , that did me in.
On the other hand, the special effects were great, and the Imax experience was pretty good.
By the same token, may I suggest that those of you that may not have seen the first "The 300 Spartans" movie, check it out.