I have been using Steam since 2004 when VALVe released Half-Life 2 for sale.
I purchased the physical boxed version of Half-Life 2 from a Fry's Electronics.
I haven't had many problems with Steam only two that I know of.
One of which in 2005 the download of Half-Life 2 would restart which got fixed.
Then this Offline Mode get set to Online Mode when I'm connected to the internet which only started happening to me in 2010.
Both Fallout: New Vegas and The Elder Scrolls V: Skyrim Legendary Edition have been leaked in gog.com's API. Since then though a gog.com employee made it hidden.
It was on a gog.com forum members leak named SPCM. So far everything on his leak has been released for sale on gog.com so far.
There are still more video games from his leak to be released for sale on gog.com. Of which Fallout: New Vegas and The Elder Scrolls V: Skyrim Legendary Edition are listed.
Then there was a leak by another person who said The Elder Scrolls IV: Oblivion will be released for sale on gog.com, but I think this persons leak so far is fake?
The Elder Scrolls IV: Oblivion should be released for sale on gog.com though if Fallout: New Vegas and The Elder Scrolls V: Skyrim Legendary Edition will be released for sale on gog.com.
Even Doom 3, Doom 3: Resurrection of Evil, Quake IV, and Fallout 3 should be released for sale on gog.com as well. Possibly even BRINk, Hunted: The Demon's Forge, and RAGE and Dishonored.