It's an inherently pulsed design, so the duration of energy production isn't a problem. It would be the same short duration in a production power plant. Many other designs are also pulsed.

What is a problem is that they simply measured the energy output of a small portion of fuel to the energy absorbed by that fuel. If you take into account things like the large energy losses in powering the lasers, they're actually pretty far from breakeven.

By contrast, the JET tokamak in the UK is expected by many to achieve real overall breakeven by 2020.

I stand corrected, thanks! I guess I'd need to add "sustained" to my shopping list of implied necessary criteria.

Add in 'with a practical mass budget' as well. Right now the best known way to produce power from fusion is to build a star, and put solar panels around it.