So whereever there was something to develop I could do it most efficiently using VB and reusing components or single methods I already developed. I also have some little experience with "language hopping" by using a little Python here and more PHP over there.
The experience tells me that every language has its own pitfalls and while hopping from one to the other you either trap in the beginners problems like missing a semicolon here or mixing up indentation there. If you can focus on one language which can be used to do everything then you should prefer that - you are simply more efficient in programming.
The two major benefits of focusing on one language:
- Easier reusability of components and libraries you already created.
- Better knowledge of the language and the pitfalls because you have more experience on the particular language.
Related post: The programming language.