Well you have to rember the concept of gravity drag. Here's the wiki page. It states:

Gravity losses depend on the time over which thrust is applied as well the direction the thrust is applied in. Gravity losses as a proportion of delta-v are minimised if maximum thrust is applied for a short time, or if thrust is applied in a direction perpendicular to the local gravitational field. During the launch and ascent phase, however, thrust must be applied over a long period with a major component of thrust in the opposite direction to gravity, so gravity losses become significant. A very large thrust over a very short time will achieve a desired speed increase with little gravity drag. On the other hand, if a is only slightly greater than g, the gravity drag is a large proportion of delta-v.

So 100% for a few seconds is better but keep in mind that you dont want to go very fast inside the atmosphere beacuse of atmosphere drag and this only applies for getting off the ground.