Apple continues the myth that you need XEON to be a high-end professional workstation, and this is simply not the case. The reality is that most benchmarks between XEON and i7 are neck-and-neck, not more then a few % +/- in numbers, and in some cases, the i7 actually does better in situations that consumers actual will do more often. Lets put it this way, NO XEON delivers the same percentage of improved performance as the percentage of increased price, period.
This is an attempt to trump up the profit margin on an aging product line by introducing supposedly more premium components, adding a significant Apple Tax on top of that, and then using vapid marketing claims to dupe consumers into believing they need this if they think they are professionals. Nobody needs a $3000+ iMac, period.
Also the reality of claiming "server grade" in a workstation is false. Most server CPUs today value power efficiency vs performance, opting for slower operational performance to reduce power usage. This is because servers are always on and chugging away at a little bits of data constantly. They do not deliver burst of maximum performance like what would be demanded on a workstation when you hit the compile, render or analyse buttons in your code, graphics or engineering application. Individually most server CPU's are not optimized for the kinds of operations that professionals demand from their desktops, so you are paying a premium price on something that will not translate to real world improvement of your day-to-day activities vs a much cheaper consumer level CPU.
Also the claims of improved reliability and longevity of using enterprise server grade components are dubious at best. When was the last time your RAM or CPU burned out prematurely? How often does your RAM generate an error that would ruin your entire day? The idea that you need enterprise features like ECC RAM and always-on server grade CPU for a workstation is pure ********.
This is another way that Apple misses the mark at understanding what professionals need and demand from their products, increased price and more ******** is usually never the key specifications that professionals demand of their next workstation purchase.