Microsoft custom vision vs Tensorflow model?
There are many differences as these are inherently complete different products with different goals.

customvision

[+] cloud deployment comes out of the box (including a rest API)
[+] labelling tool to add data and label them
[-] you have no control over the learning algorithm
[-] difficult to run your model locally/completely for free

tensorflow (or any framework really)

[-] you need deploy your model yourself
[-] you need to manage your data yourself
[+] you have full control over your network and how you train it
[+] you can embed your model into your code, run it locally, whatever you feel like