If you're writing a programming language, Lisp's terse syntax makes writing the boring parts like the parser very simple. That's why many of these cool projects use it.

But for the more everyday tasks, other languages work just fine. Lisp isn't always going to be a big productivity win over Ruby or Python. If you're looking at it from that angle, you'll be disappointed.

But yes, it's worth reading On Lisp and SICP, and working through the examples. Afterward you'll find yourself missing features that Lisp has when you work with other languages; at that point you can make an informed decision which one fits your problem best.