I did some testing today with external USB 3.0 IDE/SATA adapter and Crucial MX500 SSD.
The game loading time speed difference compared to Xbox internal HDD was surprising.
So.. next payday I am probably going to buy an external SSD for my console and move my more commonly used and bigger games on it. The HDD vs. SSD price difference is quite big and the speed gains with small "arcade" games does not matter so much... If game launches in 5 or 10 seconds - both acceptable, but 1 minute, versus 2 minutes and 11 seconds... that is a big difference.