All this is true. Similar issues arise in MIT Scheme as well. This can be partially alleviated by having specialized versions of VECTOR-SET! etc that avoid bo

All this is true. Similar issues arise in MIT Scheme as well. This can be partially alleviated by having specialized versions of VECTOR-SET! etc that avoid boxing floats. Presumably there are compiler optimizations focused on faster numerics as well. Anyway, for the purpose doing SICM-style problems (which are generally not computationally intensive), it's certainly fast enough.