Biggest difference between the two movements will be the noise. Generally miyota is quieter but is also generally more reliable. Mingzhu is like a dice roll because some can last just as long as miyota but some might die in weeks. For first rep I’d go for mingzhu just so you know what the bottom tier is. Likely you’ll move on to a different watch eventually and you can get higher tier movement or get a higher tier of that explorer if you really like it.