Dynamic cloth usually animates great, once you've got the hang of it. You might never want to go back to conformers, especially for items like long dresses, skirts, and other loose clothing. The P6-specific marketplace continues to grow, but you've already got three years of P5 merchandise available, and it all works in P6. Victoria, Mike, and the rest of the DAZ gang will work in P6. So do their injection morphs. So does their clothing. The crosstalk fix introduced in P5 often prevents matching clothing morphs from working automatically; you may often have to set the clothing morphs manually. But other than tweaking the bump and ambient settings on some materials, there are few if any problems. In fact, P6's new global crease-angle function should even prevent the smoothing glitches that often occur in P5. The short answer is: yes, it's backward-compatible.