I work at one of the more upscale MD hotels and the pay is still terrible. Roughly around $7 hourly after taxes.
You will go home some days with a measly $5-$10 in your pocket because the parking rates are so high and the hotel itself is so inefficiently run that people are hesitant to leave tips.
Large events are terribly mismanaged with valet ramps getting backed up by unattended vehicles, parking garages getting full, and slow hotel bellhops. You will work extra hard on these days and rarely will you feel fairly compensated.
Promotion within the company really depends on who's your friend and not so much on the work you've put in.