Diablo III – Is Hero Left-Handed or Right-Handed?

Since it seems that this question hasn't received a comprehensive answer, here's my best attempt at a full list of all of the differences between Hardcore and Normal (Softcore) modes:

In Hardcore, you:

• Will lose the ability to play your character permanently upon your character's death. You will also have the option to archive a profile of your dead character (playtime, level, appearance, cause of death) in your "Hall of Fallen Heroes" for posterity.

• Will lose all of your character's equipped items, all items in your character's inventory, and all items equipped on your Followers when your character dies. Any items in your Stash, as well as your Gold and Blacksmith/Jeweler status, are retained (and are shared between all of your present and future Hardcore characters).

• Have a separate stash, gold pool, and Blacksmith/Jeweler than your Normal mode characters. There is a dedicated Hardcore-only Auction House, and Blizzard has stated that there will not be a Real-Money Hardcore Auction House. Hardcore mode is an entirely separate ecosystem than Normal mode.

• Cannot trade items back and forth between Hardcore and Normal characters.

• Cannot join a game with non-Hardcore characters (and they cannot join yours).

• Can earn special Achievements for killing bosses and reaching level thresholds on a Hardcore character. Many of these Achievements have special rewards, such as banner designs.

Additionally:

• There are no innate differences in the strength of a Hardcore character versus a Normal character.

• So far, there is no evidence of any difference in the strength of monsters, quality of loot drops, or anything else that affects gameplay aside from the fact that your character cannot be resurrected upon death.

The disadvantage of elective mode is that it makes it much easier for you to make some really poor skill choices.

Another disadvantage of elective mode is that it allows you to accidentally drag skills off your action bar. EDIT: Please note that as of patch 1.0.4, skills can only be dragged off the action bar when the skill menu is open, preventing this from being an issue moving forward.

The idea of the "non-elective" layout is to help guide new players into taking balanced builds, that incorporate a good mix of primary offense, secondary offense, defense, and utility.

For example, in elective mode, a wizard could choose to use no signature spells. This means that once they run out of arcane energy, they'd have to resort to melee. While melee builds for wizards are viable, ones that involve swinging a weapon with no arcane skills boosting damage are going to be less than optimal.

The advantage of elective mode is that it gives experienced players much more flexibility in their skill builds, and gives the freedom to try some unusual, but potentially viable, builds.

As James has pointed out, it also allows you greater control over the binding of keys/buttons to skills, letting you use setups that may feel more natural or easier to use than those imposed by the non-elective version.