I wouldn't want my family "set" for life as bad as that sounds. That breeds entitlement. They are the most honest, hard working, humblest, and wisest people I know because they aren't set for life and because of the lives they have led. Someones character is the most important thing to me, not their money. My family would still be fine without the money. They wouldn't be living a life without worries but they've done fine up til now and they'll continue to be OK.
My family would be devastated to lose me even I could have left them with millions and millions more. I know for a fact that they wouldn't care about the money, even while I was long gone. They live a conservative life, money wise. If I did claim the lump sum, I'd leave it all in my dad's name and quite honestly, I can totally see him taking $10 million at most for my mom, brother, and grandparents to live off comfortably for the rest of their days and then donating the hundreds of millions left in my name to things that they knew were important to me so that my name lives on in their world. I know my mom would love that.
I see the benefits of your choice but that wouldnt be my choice. Difference of opinion I guess.