RE: What you got to show for it???
3D is a bit of a myth. Many of the maneuvers considered to be 3D have been around for decades.
Just because an airplane cannot do all of the hovering/vertical maneuvers of 3D doesn't mean that the plane cannot perform aerobatics.
Sport planes are basically advanced trainers and are aerobatic.
Sport pilots are generally pilots not commited to any one discipline, be it 3D, pattern, combat, formation, scale, racing, multis, etc.
Many people have busy lives and are unable to practice frequently enough to compete. But these people still enjoy a spirited ship that does not require a very high level of proficiency to operate.
We all fly models for different reasons. Some seek self esteem, some seek relaxation, some enjoy the friendships. The planes you choose to fly are often linked to your purpose for flying.
Some of us are revolting against the precision and conformity demanded by the busy airspace system here in the USA. The very thought of flying an unscripted and spontanious flight is nearly a blissful dream.
On the other hand, some people have very mundane jobs and they seek to challenge themselves and to inject precision and performance into thier lives.
You have stated that you fly 3 D. May I ask what you get out of it ?