Hi there! At Snipcart we are currently doing exactly that. We are progressively migrating our Saas from Backbone to Vue.js, and just wrote a blog post that can answer all of your questions: https://snipcart.com/blog/progressive-migration-backbone-vue...

For us, it has been a really positive experience so far and we LOVE working with Vue.js. The transition between the two frameworks has been really smooth so far, and I'm sure it can benefit your project too ;)