Matter of opinion...IMO
Any type of system has merit, depending on the user and what the user wants.
Example...I don't like the idea of owning a system where I cannot replace failed/damaged components. I'm not the smartest guy in the world, but I can read and comprehend all the docuementation that exists for doing such...on a desktop. Soooo...for me, owning a laptop or netbook or mini or all-in-one desktop...is out of the question.
On the other hand...any one of those would be perfectly fine for my brother, who has no interest in learning how to understand the sophisticated instrucment we call a PC. He also knows that he can count on me to assist him, when things go wrong...rather than just sit there fuming and highly irritated
Since it seems that many users prefer these systems that don't even come with a disk which permits easy repair/reinstall of the O/S...there is merit to them. They sell. I see the principal disadvantages related to troubleshooting problems (because there will be problems), replacing components, and upgrading components when some would would think that purchasing a new system is the only alternative.
So...the key is knowing who you are and what you expect out of a system...and how much time/energy you are willing to invest when things go wrong.
Then...buy whatever you can live with
I will add...if you elect to purchase any one of the types of systems I would shy away from...consider carefully the warranty provisions and the provisions for repair.
And...make backups of your system for that malware or Windows snafu that is sure to come your way.
Some think that less is more...I don't think that applies to computers for a user with a realistic expectation of what will transpire in the future. Less space means more heat that is confined in one area...excessive heat is the greatest enemy of a computer, IMO.
Just my take...