>>7
How is SBCL's memory usage terrible? It's standard behavior, intended to improve memory allocation throughput, is to allocate a certain, easily changable, amount of memory when the image is loaded.
>>9
It wouldn't take all that much effort to get SBCL to run on ARM (as it can be bootstrapped from CLs that do run on arm, like CCL). Adding an ARM backend would take a bit more work, and bootstrapping from C doesn't really help.