If you prefer to not view your files as a huge mess of plain text formatted to look like programming code and requiring herculean amounts of scrolling, you might want to check out CR2Builder. It uses a tree view to make editing the relevant parts easier, and doesn't load any morph deltas into memory to keep things running smooth, even with huge PZ3/CR2 files. It also has many Poser-specific time-saving features that simply don't exist in other editors, since it was written specifically for dealing with Poser's file types.