RisingFury B-1A had a capsule but the B-1B does not.
The only "fixed wing" aircraft to go beyond the testing stages with a capsule ejection system was the F-111.
Capt. Brian Udell a F-15E pilot survived, his WSO did not.
A description of his equipment from the linked article.
"His helmet and oxygen mask had been ripped from his head, and his earplugs snatched from his ears. His gloves and watch also were torn off. All his pens and flight suit patches were gone. His wallet and a water bottle had blasted through the bottom of his G-suit pockets, with the zippers still closed. Underneath his flight suit, his T-shirt looked as though someone had taken a razor blade and shredded it. And the laces on his boots were imbedded into the leather."
With the SR-71 Breakup I find this the most telling piece of it (At least on the subject of ejection at high speeds and altitudes.)
"The pressure suit was inflated, so I knew an emergency oxygen cylinder in the seat kit attached to my parachute harness was functioning. It not only supplied breathing oxygen, but also pressurized the suit, preventing my blood from boiling at extremely high altitudes. I didn't appreciate it at the time, but the suit's pressurization had also provided physical protection from intense buffeting and g-forces. That inflated suit had become my own escape capsule."
Another interesting paragraph.
"Extracting myself from the parachute harness, I discovered the source of those flapping-strap noises heard on the way down. My seat belt and shoulder harness were still draped around me, attached and latched. The lap belt had been shredded on each side of my hips, where the straps had fed through knurled adjustment rollers. The shoulder harness had shredded in a similar manner across my back. The ejection seat had never left the airplane. I had been ripped out of it by the extreme forces, with the seat belt and shoulder harness still fastened."
Also the WSO did not survive.
A
M-21 crew has also survived a mach 3+ ejection (all though the Launch Control Officer drowned after landing)
Most pilots do not survive supersonic ejection.
From what information I can find, Ejecting at supersonic speeds with out adequate protection, in the form of a pressure suit, is going to kill you unless you are really lucky and even then you are going to have a whole lot of other problems. With an operational Pressure suit and equipment your odds are probably 50/50.
It is my opinion that space flight has got past the experimental stage as far as getting in to space. And that we have to do our best to ensure crew survivability. Soyuz has proven that it is possible to create a safe and reliable launch system (true after some early problems) and any competitor or replacement should be able to provide a better survival probability.