I actually tried and did not like 5.0. The advantages seemed few, such as being able to lock a structure; however, some of the bloating of menues and the highlight function did not appeal to me.
BTW, I found a simple, perhaps too obvious, way to lock outlines and such -- just draw them as packages and make devices for them. The symbol is just the name or size, which can be added to the schematic, requires no electrical connections, and doesn't affect ERC.
John