It is dependent ... of use!
A standalone unit is very helpfull but if you use it regularly. Another condition is skill and understanding that you do.
The standalone unit gives you full freedom. It works by itself and it has not any dependencies from what you do. Only switching ignition off is being the reason for a choice to act - to be in research or forget about all and go to drink coffee in the cafe on a fuel station. The modern Garmin interface is very closest to the perfection. I would dare to call it an ecosystem. No intentional action is needed because subconscious actions will lead to any goal.

Only one imperative requirement I have is route support. In this case one can estimate and see any imagined movement to the right or left without to interruption of the current route. But route manager is the default function for the latest devices.

I am sincerely seeking apps to Android like Garmin but it is no success. It is only a decision for direct point to point navigation like a list of paper what contains names or numbers of roads on road signs. It is not bad if you want to reach a hotel and to go to sleep. But I had not found any worthy alternative for Garmin. Give me if you know!!! Nowadays I love my smartphone because his resource is knowledge database of all world. I always use his options for planning and especially on the last mile. But when I am driving the route only wireless calls i need from it. All other manipulation put me in a stupor and I become the potentially dangerous driver.

I will not forget of course to name the shortcomings of a standalone unit.
The first is absent of alternative maps. In some regions it is a very crucial factor. For example Here map is inadequate in Russia. It is outdated and contains many errors. In some areas it is just bare field! Maps for Android are not better at all but one always finds an acceptable source.
The second is an extra expense for a device. Everything is simple here. Or expenses will be depreciated by the total cost of numerous and frequent trips either you can afford the next man toy.

P.S. I know many people that have a Chartplotter for $1...000 dollars but they use it for the route to the saved point only. But I do not know anyone who truly familiar with the depths on his lake without echosounder for 80 dollars at least. The standalone unit is incredible only if you know all possibility of its.