The reserve pilots are former active duty pilots, many of them retired after two decades of service. These pilots often left active duty to fly as commercial pilots, but joined the reserves so they could continue to fly the more exciting military aircraft they had spent years working with. While the reservists don't fly as many hours (in military aircraft) as their active duty counterparts, they do have experience, and are more mature in years. Reservist bomber crews also tend to stay together longer, and this improves their teamwork and overall capabilities.
The army has found the same pattern with combat troops. Reservist tank and artillery crews often best their active duty counterparts in competitions.
Remember, however, that these measure individual vehicle crews or single planes. It is true that at the lowest level, reservists are often better. No National Guard division, however, is going to be better than an active component division. Same with brigades. The reservists can be better than the active services right up until you get to company level--the level of local units. At company level and below, the same personnel will train together for years, leading to excellent performance. This is especially true over the last twenty or thirty years as the country club feel of reserve units (especially Guard) declined with greater responsibilities and resources.
But once you get above company levels, reservists don't get the same opportunity to train together as active forces do, so quality of reservists does not match active forces for the most part. But the experience is still there, so once a reserve unit is mobilized it can use the training time to build on its experience and become an excellent combat unit.
This applies to ground units, mostly, since we don't plug small reserve units into larger active formations. It would actually probably make more sense to limit Guard units to battalions to be plugged into active brigades or used independently. But the Guard is politically powerful. And there is the issue of unit identification and pride that would suffer. So maybe we'd regret losing that by revamping the Guard.
In a sense, the active Army has done an end run around the Guard by making the brigade rather than the division the basic maneuver unit. When everybody is at a lower echelon of deployment, we haven't singled the Guard out. And it is easier to prepare a Guard brigade for war than gearing up an entire division scattered across perhaps many states. We've been mobilizing brigades for combat for many years now and the Guard's units have performed well.
The Air Force has been able to integrate their reservists into the active forces better. But it is easier to plug their reserve units in to the active component when many missions are simply single-plane runs.
Our reserves are truly outstanding. They are both numerous and high quality. If we sent just our reserves to war, there are few active militaries that could beat our reservists without relying on overwhelming numbers. If our enemies grant us the luxury of time, of course.
