My best advice is to rely on Microsoft's Office 365 suite for general productivity work and notes. OneNote is a pretty powerful tool, if you don't mind the purple/violet... but you can always change that.
I use Microsoft for my contacts and e-mail services too, as I find Outlook to be a robust and solid service both in managing contacts and with e-mails. The Outlook app on macOS is well designed and it offers, in my opinion, even a better experience than what you get on Windows 10.
Having the contacts in Outlook allows me to sync them to every device with their native contact apps, meaning Contacts in macOS and iOS and the native phone book on my Samsung Galaxy S8+ and Gear S3. All the entries are complete and every detail syncs correctly and flawlessly across every one of them.
I worked with Windows full-time for two years and I endlessly tweaked and optimized it to my liking. It is flexible, powerful and a good choice. But I got back to the Mac as I missed the more refined and polished experience I had with it and, aside from the UI, which is a personal preference, I find that the level of optimization and stability you get with the Mac is still unrivaled even in Surface devices.
Every program I used on Windows either works on macOS, too, or it has an equally functional or better counterpart. The Office suite offers a little less functions on the Mac but a better UI and graphical layout (and you can even change the Exchange account's names in Outlook for macOS, but you can't do that in Windows without MFCMAPI), the medical imaging software I can use on the Mac is superior from any non-crazily priced offer on Windows (Horos/OsiriX are Mac only and they're the best for my needs), Capture One, Affinity Photo, Transmission and Plex work equally well and I prefer Logic and Final Cut to Audition and Premiere (matters of interface and access to advanced functions, so could be considered personal preference).
The integration between my Apple stuff and my Android smartphone is seamless, as it was that between my Windows main workstation, my Windows laptop, my iPad and my iPhone back when I was mainly Windows-based. Now that I'm back on the Mac I have re-discovered how functional and reliable iCloud is. What I miss the most on Android is photo synchronization and in some ways I feel that this is a weak link, but Google Photo is good enough and the hardware of the Galaxy is stunning so it compensates for that!
Hardware-wise, I think you're set either way. There's excellent hardware on both sides. I currently use a Galaxy, which is quick, powerful, great battery life, a stunning display, the best I've ever seen, and feels great. Only shortcomings I see, strange as it may seem, is the fact that the screen doesn't light up when I get a notification so I have to press a button or whatever to glance at it if the screen is off. Some medical apps work better or exist only for iOS, too, so do some facility/nation specific drugs apps that I'd like to use on my mobile but can't. But hey, the Galaxy has got an headphone jack, so that's good.
I get my phones on contracts so they're practically free of charge, no big deal for me to pick up an iPhone 8 Plus the next year, as I hate that friggin' notch, or a Galaxy Note if I don't feel the need to fully complete the iCloud integration. I think that in your situation I'd list the software I have and then pick the OS which I like the most and, if it's a tie, the hardware I like the most (in my case it's Apple for everything but the smartphone and the watch).
