Upgrade from P3D 5.1 to 5.3 is it worth the effort? I'm not a computer expert! :-)) I have seen the improvements in 5.3, but do I need to change all the scenery as well?

Depends where you have them installed. If you have done it correctly and all are installed in the add-ons folder, it shouldn't be any problem.

Thanks Riccardo! Yes I did everything as recommended. Just some of the major airports, would be a waste of money. Tks again for your reply! 

the only things i think you would have to update would be fslabs and activesky..as theyr'e both rebuilt with fresh version numbers after every p3d update

steve