going to Macau this Sept. which is better MOP or HKD

hi, azam from Kuala Lumpur... sightseeing as much as possible with my beloved Nikon.
which is better currency/value - HKD or MOP?
coz I might wanna hop-on/off public transport...or local tourist spots (no plan yet)
or do they a day pass for public buses?
appreciate all responses , thx in advance