Go for the framework that lets you develop quicker. The truth is that there's no framework on earth that has solved the 'scaling' problem for you. Anyone who says '<framework x> doesn't scale' in all probability has never scaled anything.

Scaling isn't even a real, real problem you need to worry about until you're a top 1000 site at minimum, or > 10MM page views a day. At numbers past that, no framework is going to magically solve your database partitioning problems.