I use embedded processors. I don't know of any that don't use 2s complement. There are only a handful of increasingly irreverent processors that are big endian. And x86 real mode processors are long in the tooth.

There other thing is the ratio of processing power vs memory size is very high for embedded machines. You have processors that can hold their own against a 486 but only have 16k of RAM. And the marginal cost of performance is low. A lot of devices spend most of their time doing utterly nothing.