eBike technology explained

Hey everyone!

I've been diving deeper into eBike tech lately, especially as I'm thinking about upgrading my old hardtail mountain bike into an eMTB for some serious trail riding. I'm curious about the nitty-gritty of how different motor controllers work – like, beyond just the wattage, what makes one feel smoother or more efficient than another, especially on steep climbs? Are there specific controller features or parameters that DIY builders look for to really dial in the ride feel? Would love to hear your insights or experiences with swapping them out!