I used to use Casa, but I switched to Nunchuk because their mobile wallet is vastly superior. Nunchuk allows you to have more granular control over your setup whereas Casa gives you a simpler product that just works. Casa also deals in shitcoins now.
I haven't used unchained, but I've only heard good things about them. I also haven't messed with inheritance plans at all. I remember hearing the guy who was building the inheritance product at Unchained talking about it on a podcast, and he seemed very knowledgeable about it. They work hard to make sure the legal aspects are all ironed out as well.