In practice nowadays there's little difference in working on a Mac or PC. If you're using anything later than InDesign CS6 on a Mac you need to be running the newer OSs.
These are the system requirements for the various InDesign CC versions: System requirements for Adobe InDesign CC for Mac and Windows OS
You have brought up several issues, both a specific question and a general question.
Tackling the specific question, in terms of accepting a “few-years-old MacBook Pro” which is already at least six years old, don't do it! You will likely have problems efficiently running the latest MacOS version or for that matter a MacOS version that supports the latest CC application versions.
In terms of the general question …
I have both a new MacBook Pro as well as several Windows 7 x64 systems, all less than four years old. Neither is objectively “better” than the other in terms of using Adobe applications (note that I am a 25 year Adobe employee dealing with workflow and interoperability issues and use these products extensively to say the least). There is no difference in reliability or performance with comparably-configured Mac and Windows-based systems. Systems with large amounts of memory, SSDs (solid state disks), high processor speeds with multiple cores, smoking graphic cards, and HiDPI 4K (or greater) monitors are available for both. And there is no difference in output quality, either for print or display, based on upon which platform the content was created and edited on. There is certainly no “that huge an advantage to using a Mac for graphic design work.” The only difference which I will point out is that operating system updates from Apple do tend to cause application compatibility issues much more often than OS updates from Microsoft. Committing to Macs also effectively commits you to OS updates and application updates on a fairly regular basis which in turn pretty much forces you into system replacements on a more frequent basis that you may prefer.
What is true is that users have personal preferences based either on how a system looks and feels, how they like to interact (or not) with the underlying system software and file systems, perceptions about how they are regarded in terms of what gear they use, and/or even snobbery. Historically, MacOS had a usable graphical user interface at least six to eight years prior to the release of Windows 3.x, the first really usable version of Windows with graphic arts software and early graphic artists simply used what was initially available. But in the end, its a personal thing just like whether you drive a Mercedes, a Lexus, a Honda, a Ford, or a Chevrolet – all will get you where you need to go.
Good luck with your decision!
Thanks to both of you for the helpful answers! I've heard so much sMac talk over the years, that I half believed that Mac was some sort of holy grail. Truth is, I had a hard enough time switching to Windows 10, so the thought of having to learn new OS tricks appeals to this old dog about as much as a month in the cone of shame. Derek's comments about the technical specs clinches it, though. It sounds like I wouldn't be able to work on this particular machine, anyway.
Oh, and I live in Northern Idaho, so it's a Subaru, which really does have a better chance of getting me where I need to go in all this snow! ;^)
Good luck. Keep in touch on this forum!
Ah, Subarus. A few years ago Subaru ran ads/commercials about the special feeling people had towards their car. But it was really true!
People loved the fact that their Subaru was extremely reliable and just ran and ran forever with only basic maintenance.
I had a Subaru for 15 years and it probably was still good for several more years when I got another car. Oh well . . . .
The only concern I'd have is with Fonts, if using OTF fonts then all is good.
But some mac font types won't work on a PC, so if you got designer fonts from a Mac then you'd have an issue.
I've also had some fonts that refuse to install on a Mac.