Before winning the majority of Hollywood studio support, those partial to the Blu-ray format have primarily relied on a few points to make their case: more storage and rocketing sales at the ratio of 2:1 to HD DVD. HD DVD was a more stable platform with more features on almost every disc that was offered in both.

When Wilson compared the same discs in each format, Harry Potter and 300, HD DVD had many, many more features. Proof is in the pudding:

Compare the two editions of 300:

Blu-ray could technically support a lot of that functionality, according to the spec, but the trick here is that most of the spec is not and still isn't mandatory. And even when all the Blu-ray players on the market are up to the final spec, whenever that may be, the majority of the original players will still not support extras, so why would anyone develop those extras? They won't. A stair-stepped rollout of what each player must have to be spec compliant has severely limited the Blu format, despite all that great storage capacity.

And this might take a very long time to fix, if it ever does.

Source- http://gizmodo.com/346689/why-i-wish-hd-dvd-had-won-the-format-that-loved-me