they're quite nice and rather cheap now considering that a year or so ago a 400gb card was well over 100dollars, I would just advise you also buy a USB3.0 SD card reader with a decent rating on amazon if you're going with this card because you'll probably want to shift over all the games you have on your current micro SD card and then build on top of it and you can just copy paste the entire SD card directory from the card you have onto a folder on your PC and then from there onto the new card with no issues (in my experience)
If you haven't changed the SD card in your Switch before the one thing you should know is that you don't have to worry about your save files for the games, they're all stored in the Switch storage itself, so even if you completely fuck up transferring files or if you're too lazy to bring over the old cards games all you will be losing is the game files and the pics / videos that you've captured in games, those are likely to be stored on the SD card if you took more than 1k screenshots as that is all the base unit can store of pics before going to SD card for them.
I'm off to bed though, if there's anything else you're asking regarding shifting SD card on the Switch I'll check back in tomorrow and see if I can help more. :)
edit - https://www.amazon.com/UGREEN-Reader-Portable-Adapter-Windows/dp/B0779V61XB/ref=sr_1_7?crid=3A2UKQB54VBWI&keywords=usb+micro+sd+reader&qid=1565500543&s=electronics&sprefix=usb+micro+sd%2Celectronics%2C215&sr=1-7
It was one of those I used to shift my old SD card contents to the PC then onto the 400GB card.
Ugreen do some nice small little things which the Switch works well with, they've got a USB Lan adapter as well that costs around 10e and works great to get a wired connection with the Switch when it's in dock or with a USBC to full USB adapter you can even use Wired ethernet while playing in handheld mode.
Fancy hearing me on an amateur podcast with friends gushing over one of my favourite games? https://youtu.be/1I7JfMMxhf8