About a year ago, I was introduced to a new project using the catalog model, and my personal transition has been difficult. My final verdict, is that there's no additional benefit, and often caused more deployment issues since it requires tighter integration and coordination with SQL Agent configurations. And it gets more complicated with source control (we use Team Foundation), and deploying to multiple SQL instances.

I maybe can see some benefit over the new Catalog Model over previous file/package deployments, if you're brand new to SSIS. But there's nothing I haven't done before through configuration files, smart parameter and variable utilization (which still is required with the Catalog Model.)

A few of my colleagues are of the same opinion, and the ramp-up time and training has cost us more time than it should have saved. I would stick with what's working, and wait until Catalog Model matures.

In terms of scaling, your XML configurations should still be very viable at least through SQL 2014, I imagine.

It might depend on your team, but for the teams I'm working for...ROI on transition has not been good. retraining and refactoring costs wasted more time/money overall.