I much prefer a GLADOS-type AI voice than one that approximates an endlessly happy chipper enthusiastic personal assistant. I think the AI tutor is probably the strongest for actual real-world value delivered the rest of them are cool but a bit questionable as far as actual pragmatic usefulness.

It'd be cool if an AI calling the another AI would recognize it'd talking to an AI and then they agree to ditch the fake conversational tone and just shift into a high-bandwidth modem pitch to rapidly exchange information. Or upgradable offensive capabilities to outmaneuver the customer service agents when they try to decline your warranty or whatever.