The good developers have pretty much done away with loading stoppages with background streaming while you play. I don't think it's going to be a problem.
"On a basic level, the challenge here for developers will be to read data quickly enough from the optical drive in order to make use of that prodigious 8GB of RAM - we can foresee background installs as part of the picture here, loading up enough gameplay into memory to get going while more data is streamed onto HDD in the background. On PS3, we already see a number of titles that 'stealth install' onto the hard drive (many of them running on Unreal Engine 3, and Capcom's Dragon's Dogma being another) where read speeds are so much higher - even slower 2.5-inch drives can reach 100MB/s in their best case scenarios. Our hope is that the era of mandatory installs that keep you from getting at the game are a thing of the past. The signs look good: making the experience of using the console as friction-free as possible was a key part of Sony's presentation last night." http://www.eurogamer.net/articles/df-hardware-spec-analysis-playstation-4
