I am not familiar enough with the engineering of rear suspension to say what the pros and cons are. I do recall reading very old threads discussing this issue that raised concerns that "true" type coilovers may place undue stress on the upper strut mounting points because they were not designed for that level of load.
I suspect for normal driving, there's absolutely zero difference. Maybe at the limits of of a race track, there's some advantage gained from one style or the other.
There may also be a simple manufacturing issue where certain coilover companies find it more economical to make it one way or the other
Lastly, be advised that if you switch to a "true" type coilover, DO NOT PURCHASE the SPL Mid-Link. As the spring is wrapped around the damper, there is no need for an arm with a spring bucket, so you will use this instead:
Adjustable Rear Toe Arms for the Nissan 370Z and Infiniti G37 | SPL Parts
Same adjustability, no bucket.