I have a t2000 myself and it is a fine box aside from being EOL’ed at 11.3, t1000 also, I recommend avoiding those except for data center use only.
I specifically picked up the T4 as it looks like Oracle is planning to become much more agressive with their update schedule, 11.4 Sept 2018, rumors (from Oracle seminars) strongly suggest that 11.5 will be out next year.
I respectfully disagree on the illumos community. drivers and other HW specific items aside, for decades Sun, and now Oracle state that the OS is compiled from the same base code. I’ve been in/using/following the illumos+OpenIndiana community almost since the get-go, and my person opinion (and you know what those are worth! ) are that many of the developers have a bias against SPARC.
That out of the way, I’ve noticed that the last, maybe 6 months or so, there has been a softening in the illumos community toward SPARC, along with a sharp increase in development and coding. And more directly, I’m speaking to the illumos-developer list.
Either way, Nvidia, hope you are watching, and keeping us Solaris+Solaris distro users in mind, both for the enterprise and at home. Thank you for the fine products you provide !