If you use uncompressed (or transparently compressed by the filesystem) binary, your process has mmaped the memory pages, which can be discarded and then reloaded, as needed.

If you use self-extractor, your process has dirty pages that it itself wrote, that cannot be discarded, but must be moved to swap if needed.

The more you use the same executable for multiple processes, the worse the effect is. The ro mmaped pages are shared among them all, the written pages are private to each process.

I would be surprised to see practical performance degradation in uncompressing executable code before jumping to the program on today's machine. The largest binary in my /usr/bin/ is 50 megabytes. On the other hand, for very, very large binaries it's probably faster to decompress in memory rather than load all the bits from disk.

Further, most executables aren't static these days. (I often wish they were, though!). What type of binaries have you got, and are they really so big that it's worth the hassle to compress them just to save disk space?

Just interested.