Here something I learned a while ago; Speed isn't how fast you do something (it is, but only partially), it is often a measure of whether or not you actually CAN do something.
Here is my story:
In the Mid 90's I ran an ISP. Part of my daily chores was processing logs looking for anomalies, and to gather stats needed to project out the upgrades that are needed. When I started, the logs were small and it took a few minutes to process. As the business grew, the process took longer and longer. It soon took hours to process the logs for the day. It became so problematic, that I just stopped doing them.
But business kept growing, and I needed the stats. So, I bought a new machine. The new machine could process the logs in five minutes, what took hours on the older machine. Mind you, this was one generation difference between the two machines (68040 to PPC 701), but that was all that was needed to show me that speed isn't just how long it takes, sometimes it is whether or not you do the thing you ought to do.
Seeing the price of SSDs and Spinning HD, at their current price points, there is no reason to NOT get the SSD, at whatever cost they are now. Especially for enterprise grade systems that need the IOPS, Even at $1000 for 1 TB SSD is extremely affordable speed, especially when considering you get 90,000 IOPS.
IF we're talking about 1000x faster, the speed is enough to change what we can do.