is it true that using my DeX-supported smartphone ( for example SAMSUNG Galaxy Note 9 ) to mirror the image of my smartphone to a 15.6 inches External Monitor via SAMSUNG Multiport Adapter , there is a latency involve and as a result , the performance is sluggish . Don't you agree ! Could you please comment on this ? 

But if I happen to have a 14.6 inches Android Tablet like the SAMSUNG Galaxy Tab S9 Ultra 5G (which is quite close to 15.6 inches which is my favorite form factor for a machine regardless whether it is a Smartphone or a Laptop  or a Tablet ) , it is just like having a  15.6 inches 5G smartphone.   

I am very sure the hardware manufacturer will not make a 5G smartphone which have a screen size of  15.6 inches . With a machine like the SAMSUNG Galaxy Tab S9 Ultra 5G , I guess we can forget about making a 15.6 inches 5G smartphone because having a SAMSUNG Galaxy Tab S9 Ultra 5G is just like having a 15.6 inches 5G smartphone which can serve as a Laptop , which can serve as a Tablet , and BEST OF ALL , it can serve as a 5G smartphone , which make the machine a true and a real [ Laptop/Tablet/Smartphone(ALL-in-ONE) ] machine .

COPILOT  ANSWER

You're absolutely right that using Samsung DeX with a smartphone like the Galaxy Note 9 to mirror the image on a 15.6-inch external monitor can sometimes introduce latency, leading to a sluggish performance. This latency often arises from the processing power of the phone and the speed at which it communicates with the monitor through the adapter.

The Samsung Galaxy Tab S9 Ultra 5G, on the other hand, offers a more versatile and seamless experience. With its larger 14.6-inch display, which is close to your preferred 15.6-inch form factor, it indeed provides a highly capable multi-purpose device. It can serve as a laptop, tablet, and smartphone all in one, thanks to its robust hardware and 5G capabilities.

Moreover, the Galaxy Tab S9 Ultra's dedicated hardware designed for a larger screen size means it can handle tasks more efficiently without the latency issues commonly faced when using a phone with an external monitor. This makes it an excellent choice for productivity and entertainment, embodying the true essence of a [Laptop/Tablet/Smartphone(ALL-in-ONE)] machine.

In essence, while DeX is a fantastic feature for extending the functionality of your smartphone, having a device like the Galaxy Tab S9 Ultra 5G can provide a more integrated and smoother experience, reducing the performance hiccups you might encounter with a smartphone-to-monitor setup.

Is there anything else you'd like to know or discuss?