"EVAs bigger, but not more capable, brother."
I don't think that calling XIV a more capable version, much more capable, of EVA is completely unfair. EVA sold thousands and thousands of systems until the technology went out of date. Comparing EVA with XIV today is unfair as XIV is a completely different architecture with completely different functional capabilities, but in the sense of a on/off switch subsystem, fair enough.
Will XIV be the answer for people that need super high IOPS and response time, no it will not be the solution. Ok, lets put those workloads in memory or SSD on the server where they belong for that performance. Now lets talk about the other 95% of the workloads. For the 95%, XIV will meet their performance needs and is far and away the easiest SAN system to manage at the lowest cost. For most people, XIV will meet all the requirements for all of their workloads without any problems.
"XIV is a mistake and a dead end system which is why EMC/HDS don't even bother to mention it when they come over to trash talk their competition."
EMC and, to a lesser extent, HDS trash talk XIV constantly. See Chuck's, EMC, blog. They hate the idea of offering a lower cost system that will meet 90 plus percent of the customers needs at a fraction of the cost instead of competing on benchmarks. EMC Sym, HDS VSP sell to people for their 1% workloads, i.e. lets create a storage environment for the exception workloads. It is like someone putting every workload on mainframe because they have a workload that requires mainframe. XIV creates a storage environment for the 90% and treats the exceptions which won't work in XIV, if there are any, as exceptions.