AOIs being inefficient isn’t a matter of 7.9 vs 8.0, it’s firmware v21+ (…and 20.15+), when Rockwell deprecated the direct memory access and introduced the new services for reading tags. If you’re using the legacy driver accessing AOIs is fast, if you’re not it’s subject to the limitations @pturmel mentioned.
Any slowness you’re seeing in Vision templates between 8.0.x versions is unrelated to the driver and unrelated to your use of AOIs, though Phil will surely jump on the chance to talk about how you should never use the tag() function and always use indirect properties 