I put together a post a couple years ago trying to compare neighborhoods across cities: https://medium.com/jeremy-keeshin/neighborhood-comparisons-across-cities-200b7bb6f864
I’ve recently put together a simple website/tool that lets you actually go in and enter your own comparisons of neighborhoods between cities, and then aggregates the results.
Try out the site here: http://neighborhood.thekeesh.com/
You can select which cities you want to compare, and either enter in your own comparisons, or view the results. Take a look and feel free to share it around!