From the PC side:
I think digital done right is wonderful. I can't tell you how many systems I've downloaded and installed WoW or Counter-strike, never worrying about disks or keys or updates/patches whatever. I've got some friends who are really into the slightly older Command and Conquer games (Generals, CnC3, etc) and trying to get a version that installs correctly, and can play on the lan, and the internet, and everyone is patched to the same version: it's a real hassle.
Yes, I am placing a lot of trust in Valve to not decide that I don't own those games anymore. Partly because it's Valve, and it seems like they are a pretty decent company, as companies go. Also track record. I have Half-life in steam, which I bought over a decade ago, and it's still there, ready for me to download, like, whenever. In this case, for me, that risk is worth the convenience trade-off.
That being said, I'm still REALLY hesitant to buy digital games through a console. I don't know if it is just a trust issue with MS/Sony/Nintendo, but I don't feel like those games are going to be available to me on another console/iteration/etc. Maybe that's hypocritical.