Hiring an ASP.NET MVC w/ Razor developer can significantly enhance your web application development. They can create clean, fast, and interactive web applications using Microsoft's robust framework and Razor view engine. Their knowledge in MVC architecture ensures an organized coding structure, making your project scalable and manageable. They can also integrate security features, reducing vulnerability to threats. Their ability to utilize Razor's syntax can lead to more efficient and readable coding. This can result in a well-structured, high-performance, and secure web application that can meet your business needs.