Many were surprised when Boeing got the SST contract in 1966, Lockheed's experience with high-speed flight had made them the front-runner in many people's opinion, and their delta L2000 design looked less risky, even allowing for the Mach 2.7 speed.
They were proved right, the VG 2707 proved an impractical design, the weight of the huge swing-wing mechanism was excessive, and early tests with models indicated the wings would need strengthening.
The second 2707 VG design moved the huge GE4 turbojets to the massive horizontal stabiliser, a bitter Lockheed engineer commented 'I guess they had to put 'em there to prevent them from burning the tail off!'
With the swing wings, the complex triple slotted trailing-edge flaps, leading edge flaps, all the other flight controls plus the complex droop nose, the 2707 had 59 moving surfaces, concerning to some potential pilots.
In 1969, Boeing changed the 2707 design to the -300 tailed delta.
Much more conventional, but the Mach 2.7 speed required extensive use of titainium, and those GE4's, each with some 60,000lbs of reheated thrust, would have been much noisier then even Concorde's engines.
As we all know, aircraft noise and pollution had become serious issues by 1970, the 2707 had enemies, though some were more concerned with 90% of the 2707 development coming from tax $.
Must have been quite a sight to see right-wing republicans allied with enviromentalists!
Finally, in March 1971, Congress voted by a majority of one to stop funding 2707 development, the wrong-headed initial designs had lost too much time and money.
Lockheed's design probably would have flown, though whether it would ever had entered service is another matter, the Boeing SST, though much bigger than Concorde, (230 pax), had about the same range.
I think the L2000 would have been similar.
Apart from the remains discussed previously, there was a legacy from the 2707 programme still with us, late in the project, Boeing were looking at cathode-ray tube displays for the 2707, though a flight engineer would still be required, along with plenty of conventional instuments for the Capt. and F/O.