I was torn between a used Apple laptop or a new Mac-mini and eventually bought the latter.
For some reason I believe that laptops develop more technical problems and they happen earlier than desk tops. Also, that laptops are tougher to accurately trouble-shoot and fix problems. Aren't laptops more flimsy in construction?
What do you think?
Considering Apple sources all of their parts from the same manufacturers, both would have about equal chances of having issues that aren't your fault. You could argue that mobile components get more wear than their desktop counterparts because of poor air ventilation. Apple products have some of the best heat management systems out of any laptop manufacturer, and are known to underclock their processors and GPUs, increasing lifespan. Any other "technical problem" is because you somehow damaged your computer.
As for the desktop/laptop repairability and troubleshooting, desktops win by a small margin because they are slightly more accessible than the current lineup of Apple laptops, but really not by much, especially since 2012. On the software side, they are exactly the same.
And yes, laptops are more "flimsy" than desktops. You are more prone to damage them because you are carrying them around. Apple laptops are very sturdy though, and in comparison to other laptops, they hold up very well. If you are concerned about the longlevity of your machine, Apple is the way to go.
Please note: Just because a company has the least faulty computers doesn't mean there are not any faulty ones. All computers will fail at some point, Apple computers just last longer on average. If you are this concerned, definitely look in to getting Applecare.
Best,
Matt