Re: ARM or MIPS?
ARM was famous for the best overall performance to power-consumption ratio. The "Thumb" mode (16-bit instruction words) also reduced codesize. Both these features together helped ARM dominate the portable-electronics market. Today, ARM proessor is de-facto standard of mobile-handset/cellphone market.
In other consumer devices, where power-consumption is not as important, ARM shares the market with competitors (like MIPs.) In general, MIPs is more powerful (more work done per clock-cycle) than ARM, but consume more power. For example, the vast majority of TV-decoder platforms (cable/satellite/IPTV) contain an embedded MIPs core (or more than 1.)