The advantage you get from breeding these two beasts is using the strengths of each language to offset the weakness of the other. Currently I do most of my coding with perl, C# and C++, occasionally I use Java as well. The language I choose to use depends on which language is best suited for the object I wish to create. I have projects that are tens of thousands of lines long that have some objects written in perl, others in C#, and yet others in C++. But they are all part of the same program, and each language uses the objects from the other languages. Often times Iíll choose perl to test each of the objects. That is because perl is the best at writing quick test programs. I know how to test in each language, but choose perl to save time during the testing phase. Once you have an object, it doesnít matter what language you choose to test the object with. You will get the same result whether you use perl, C#, C++, or Java. An object has interfaces, and all you need to do when testing is make sure each interface does its job. Any language that can use that objectís interface can test that. Of course this assumes you know how to call one languageís object from another language, but that isnít too difficult to learn.
It all comes down to TIMTOWTDI. You may not feel comfortable using perl to interact with another language, but that doesnít mean other people are the same way.