>>58037892
i'm (probably) the only person in PMD who can properly answer this question since almost nobody has put significant work into both PMDO and Skytemple except for me

PMDO is a lot more powerful and easier to use, but you have to reinvent the wheel pretty heavily, and it doesn't quite hit the same feel as Skytemple given that it IS ultimately a facsimile of it. The gameplay in PMDO is way better at base though, and with the tools at play you can make cool and interesting things way easier than in Skytemple, where anything that isn't bogstandard becomes either a giant creative effort to make use of vanilla moves/tools, or becomes a giant programming effort to add things via CoT or asm. Though, Skytemple definitely lets people be lazier since a lot of stuff is already built in. You also can play on DS hardware with skytemple products.

There's more than just this, but these are the main differences I'd say. Each has its plus and minuses. Lately jams have required me to focus on Skytemple but I wish PMDO had jams since it'd be a lot easier to do cool and interesting things with it...