I have the Moto X 2014 running Andrdoid 5.0, and it does not compare. The X rarely understands anything I say, even after training multiple times. It's also extremely slow to respond when it does understand. The X takes around 15 seconds to tell me the weather, while the Echo has it right away.
Capital gains tax is mentioned:
"I devised a 21st-century tax code that would establish a 14.5% flat-rate tax applied equally to all personal income, including wages, salaries, dividends, capital gains, rents and interest."