I can't recommend anyone make a trip just to walk around Ma Wan 1868, but if you happen want to stroll around Ma Wan, feel free to stroll around as you please as it's finally open versus being all walled up fairly tightly for a long time.
If you want a better view go check out the fairly new (small by plenty of standards) Ma Wan Tin Hau Temple that they built as they destroyed the old one in the old village. If you go with someone that knows Chinese, ask your query, shake the sticks until just one falls out, and ask that person to find and read you your pink future slip. However, I never can remember if you're suppose to step into the temple with your left or right foot and exit with which one, but feel free to look into that too. Additionally, on a clear day you can see some of HKIA and more.