I use Padrino exclusively now; it does everything I need while also being lightweight, fast, and modular. Since I haven't played with Rails since 3 was in beta

I use Padrino exclusively now; it does everything I need while also being lightweight, fast, and modular. Since I haven't played with Rails since 3 was in beta, I'm genuinely curious: from a purely technical standpoint, for what types of projects might Rails be a better choice than Padrino?