I may be in love. Let's get into it.
I decided that I would bite of Scheme this year. That decision was based on 1) not being ready to kiss Lisp goodbye 2) being a little lazy (not much syntactic difference between Lisp and Scheme). The decision was made clearer by Bill Clementson's blog thread "What is the best Open Source Lisp?" - especially part 2. This is where Bill says that PLT Scheme is the best OSS Lisp environment.
So, I went out and downloaded the latest copy of Dr. Scheme and started reading "Teach Yourself Scheme in Fixnum Days" that is included in the distribution. Great book for quickly coming up to speed on the major features of Scheme. Have I finished it? No. Am I writing Scheme code? Yes. There you go.
The Dr. Scheme environment is wonderful. I skipped the student levels of the language and went to Pretty Big. Unfortunately this precludes me from using the Stepper. But, I still get all the other goodies that are in the environment. Some of my favorite features: debugger (shows you the call path visually with arrows and traces the code to specifically the call the generated the error), test case boxes, and the large included set of libraries.
One of my headaches using other OSS Lisp (CLISP, CMUCL, SBCL) was that you had to go out and find CL libraries and install them by hand. Even tools like asdf and asdf-install didn't make the process painless enough for me. Many things worked well with asdf, but some things just didn't work well at all. In fact, I think that the ACL-COMPAT is not "compat" now that they changed out the ACL Net package for puri.
With Dr. Scheme, the library issue is MUCH cleaner. In fact, many of the things I've played with so far are distributed with the environment or they have PLT packages that can easily be installed through Dr. Scheme.
Another great thing about Dr. Scheme is that it's cross-platform. It works the same on my Mac, Windows, and FreeBSD boxen. The GUI is based on wxWindows, and the GUI gets the appropriate "look" for each platform. For instance, Dr. Scheme is all Aqua-fied on my Mac. On my Windows machine, it gets all Redmond-fied (boring).
So, in summary PLT Scheme is my new best friend. If you are using OSS Lisp and getting a little frustrated, or if you just want to learn Scheme, then go get Dr. Scheme now.