New to eBikes - where to start?

Hey everyone! I'm super excited to finally dive into the eBike world. I've been eyeing them for a while, and I'm thinking of converting my old mountain bike (a 26er hardtail) into an eMTB for some trail riding and longer commutes. For those of you who've done DIY conversions, what was your biggest "aha!" moment or the one piece of advice you wish you knew before you started? I'm trying to figure out if a hub motor or a mid-drive kit is better for mixed terrain, and any pointers would be amazing!