Well, personally I don't think there's a "better or worse" in this case, they are just different solutions with different pros and cons. Just try it and look which one you like better
All I know is that printkey is a local program on your computer, while aviary probably (?) wouldn't work if e.g. their server were down, but people who used it can tell you more. I haven't tried it yet so can't tell much, but simply open yourself the macro file and read how it works exactly: Edit > Configuration > Macros > Double-click on macro name (=simple text file)