There is no doubt that the VC-10 suffered from being an unwanted child, forced onto BOAC by a government trying to support the British aircraft industry. However, as BOAC were also state-owned and supported organization, the government should not have tolerated their campaign against the VC-10, which seems motivated by a burning desire to place orders with Boeing.
I believe that people who have flown both the 707 and the VC-10 are fairly unanimous that the Boeing product was a superior commercial machine, with a generally much healthier range/payload. However, in the state-controlled economy of the 1960's, once the government had given approval for Vickers to go ahead with building the VC-10, it seems incredible that their own airline were allowed to order a rival aircraft, even if it was superior in many respects.
Before this thread becomes more suited to history and nostalgia, back to technical issues. The flying controls are actuated by self-contained hydraulic units powered from the aircraft's electrical system. Redundancy is achieved by split surfaces, each powered by a different AC bus. The aircraft has 4 engine-driven generators (rather than 3 on the 707) - plus a ram-air turbine to keep some surfaces powered if all gens fail. Reversionary control is achieved by using differential hydraulic spoilers for roll and the horizontal stabilizer for pitch. The latter is the only surface that has a duplex source of power (both hydraulic).
To add to the information about speed limits; the aircraft had warning horns that sounded at the Mmo of IMn 0.886. The circuit breakers for these could be pulled and the aircraft flown up to IMn 0.925 (Mne) for "crew-training" purposes (although the autopilot was only cleared to Mmo). It's quite amazing how much "crew-training" took place on VIP tasks! In it's later years the speeds were all reduced for airworthiness reasons and with all the AAR kit hanging from the aircraft it could only be coaxed to reach the airtest limit in a gentle descent. The IMn is 0.02 higher than true, so for comparison the old Mmo was really .866 (nowadays even lower) - which puts paid to a lot of the "fastest airliner" claims. The 747-400 routinely cruises at .85 or .86 true and is still RVSM compliant at .90. The old VC10 is still faster than Airbus ships though!