If that's an analogy between Keil and SDCC, that's nonsense. I've used both. I tried using SDCC with a project two years ago and while it eventually worked, I had a couple cases during the project where I had to figure out what the compiler was doing wrong and work around it. I've never had that with Keil.

This summer I'll be working on a second revision to that project. The first thing I'm doing is converting it to Keil.

Regards,
Craig Steiner