The ultra-deep dish wheel, when done right, can be faster than a disc in many situations. ENVE has done it right with their SES 8.9 Tubular wheelset.
The 95mm deep, 24mm wide rear wheel does it better in many ways. It's lighter, with a lower moment of inertia, so it will climb better and accelerate better. 20 two-cross spoke pattern means the wheel will handle bumps better, feel better getting out of the saddle. And will be easier to control in wind, thanks to not being solid all the way through. They tested their .9 rear wheel as being within 5% of discs in most situations, and they believe that when you factor in their wheel being easier to ride, it comes out as a net plus.
When discussing ENVE's SES wheels, control, or stability is a big issue. They believe that how wheels handle in real-world wind is an important factor in riding. So they tested their wheels while clamped into actual bikes and both rode them in the world and modeled real-world conditions when designing the wheels. This is why the rear wheel is only 24mm wide. They find it interacts with frames better—and fits more frames than wider rear wheels. It's also why the front wheel is 85mm deep and 26mm wide and supported by sixteen radial spokes. It is easier to steer and plays better with the fork and tire in front.
They also believe stopping is important. So they have a molded brake track that, when combined with the depth of the rim dissipates heat better than aluminum alloy rims. A cooler brake track stops better and more predictable, and is easier on the tubular cement holding the tires to the rims. They've also included ENVE brake pads, which are designed specifically to stop ENVE rims, and are essential to the warranty.
ENVE is big on system thinking. That's why they include four ENVE valve extenders, along with titanium-shafted ENVE skewers, and put all the small parts in a nifty bag so you won't lose anything. Here's something else ENVE hands over; the fastest tire size. f you want to optimize aerodynamics, use 23mm tires; they test the fastest.
These tubular wheels offer two hub options. One is DT Swiss' 240 hubs. The other is Chris King's R45 Ceramic bearing hubs. Both hubsets have the option of cassette bodies for either Campagnolo 9/10/11 or SRAM/Shimano 10/11 cassettes (and you can buy extra bodies to swap easily). The DT Swiss come in at 1656g for the set. The Chris King weigh in at 1641g.
ENVE takes pride in building their rims and wheels in Utah. They're so confident in them that they not only have a five-year warranty on their products, but they also have a lifetime crash replacement policy where they'll replace any destroyed ENVE product for 50% of MSRP, provided the customer has the paperwork to prove original ownership.
The ENVE SES 8.9 Tubular Wheelset is ENVE's ultimate time trial setup.