It's cleaner than ARM or MIPS. AArch32 has something like 1200 instructions these days and a ton of cruft in there. AArch64 has good but not great instruction density, having nothing like ARM Thumb or RV-C.
MIPS (or at least what most people mean when they say MIPS) has all sorts of gross stuff like branch delay slots that are a pain in any non 5 stage in order design.
