Thing is people like Mark (Tipes) are the exception to the rule here. Most of these people getting itchy saying they're going to upgrade to X99 would upgrade to a wet tissue if Intel sneezed in one !
It's the same with Nvidia. The amount of people I've seen replacing 780s and 290s with 970s.. Madness.
If you're going to hang onto this rig and keep it for four or five years then sure ! by all means go with X99. It's like X58 was and X79, a lot of investment so you really need to hold onto it to get the most out of it. But most won't. Give them six months and they'll sell it at a loss to buy whatever crap Intel decide to release next.
The last time I invested more than a grand in a rig was 2001. I bought a dual P3 Xeon rig on a Marlinspike board running Windows 2000. It was an epic rig and I had it for three years before upgrading the board and CPUs to 2mb 866 Xeons.
Since then ? I've gone with mid range CPUs so I've had plenty of Intel and AMD. It was only because I had a bit of a windfall that I decided to invest in Titan Blacks and a 3970x and I fully expect that rig to last me for years and years before I even think about changing anything in it.
It's a bit of a nightmare trying to talk sense on a forum like this, given sense was chucked out of the window the day the place opened lol.
I broadly agree with your sentiments. I only upgraded to x99 simply because I had a bit of a windfall too, but I certainly agonised over whether I should spend such a sum of money on a whim !! Having done so I am not overall disappointed in any way, but in truth was it necessary for me to upgrade? The honest answer would be no. As I said in my earlier post - this current rig will have to last me if I am in any way to get some moneys worth out of it. For the same reason I am reluctant to push it to the extreme for benching - bit of fun, but at what cost if I blow my components - despite appearances I am not well heeled at all, so will have to look after what I have.
As I said earlier too - each to their own. It is not for me to dictate what others should or should not buy for whatever reason, it is always a personal decision, and I don't believe right or wrong comes in to it.
Mark

Or I just get out my Dremel and a couple of sheets of acrylic costing a fiver or so and get creative 