I've voiced my opinions on this matter, and been pretty adamant about it really. It isn't reasonable to expect perfect phase from a loudspeaker; Certainly not with today's technology. One can design to avoid rapidly moving phase shifts and try to widen the radiation pattern where summing is constructive, and those are worthwhile goals. But there are many things that prevent phase from remaining fixed at 0o, so I'm not comfortable with phrases like "time aligned" or "transient perfect".I think the best goal is the one we all strive for, and that's to avoid quick phase shifts which prevent coherent summing. Most only try to maintain this on-axis, but I would go beyond this to include a range of listening positions. That's a worthwhile goal, a requirement for uniform coverage. But to call that transient perfect is just marketing rhetoric.