The controversy of sole ownership versus partnership began more than 100 years ago when Wilbur and Orville Wright flipped a coin to see who would fly their shared airplane at Kitty Hawk. It’s still a trade-off. You can share the plane and its expenses or you can have both of them to yourself.
The advantages to individual ownership include exclusive use of your plane, lower aircraft insurance rates, and predictability. The obvious disadvantages are the higher cost of operation and the finite amount of capital available for purchasing the best plane.
The advantages of flying partnerships are numerous. A partnership allows you and a fellow pilot (or two or more) to pool cash and buy a better plane than you could on your own. It also helps reduce operating costs by sharing them with another pilot. The disadvantages to a partnership include potential conflict over times when the pilots want to use their plane and the chance that damage caused by another pilot will curtail your flying until repairs are made and paid for.
Even with these disadvantages, there are many long-term successful flying partnerships that have worked for decades.
"Man cannot discover new oceans unless he has the courage to lose sight of the shore."
-- Andre Gide