Incidentally, the Raspberry Pi Compute Module is indeed "rather unknown", which is a shame. It is amazingly useful and lets you design devices without getting into high-complexity PCBs and BGAs. You can place an SO-DIMM socket on a simple 4-layer board (adventurous types might even go with 2 layers if you don't need USB) and build a computing device that would otherwise be out of reach.

Another added bonus is the built-in flash, which is significantly more reliable than the whole SD card setup (for many reasons). Or the two CSI ports (only one is exposed on the standalone RPi board).

All in all, for anything except prototyping, this is a much better solution than a standalone RPi. In my designs, I found it to be a useful and reliable workhorse.