The T1C wing was certainly optimised for high speed cruise, as it had 38 degrees of sweepback, and high lift devices were required to get acceptable lift off the wing for takeoff and landing. It had a Vmo of 380 kts and, if I remember correctly, a Mmo of 0.93M and cruise of .885. this was later reduced to 365kts and 0.85M cruise to come into line with the T2, which at 35 degrees sweepback was a little slower. The B727 had a higher Vmo but surely not a higher Mmo, as we used to leave them standing in the cruise.
The T1 had excellent high speed handling. I remember seeing over 0.95M during our high fly exercise (cb pulled) and there was no buffet or airflow separation, even turning at 30 degreees of bank, just a slight rumble from the ailerons. During the emergency descent manouevre, the rate of descent could only be determined by use of a stopwatch and the altimeter between FL300 and FL200, as the VSI was jammed onto the bottom stop. It was in excess of 18,000 fpm, a capability the ATC soon learned to make good use of.
In the late 60's as the autoland system was developed and proved, we were initially only allowed to carry out 'autoflare' landings, with roll control provided by the pilot. After a certain number of these had been completed we moved onto full autoland, right down to Cat 3c capability. This was found to be impracticable, as in complete zero vis it was impossible to taxy or be found by the emergency services, so Cat 3b with 75 metres vis was established as the working minimum.
A further feature of the T2 was water injection for the Spey 512 engines. This was used to uprate the performance out of short and/ or hot airfields, such as the old Malta Luqa or Nicosia airfields. This provided about three minutes of sporty performance, but the water usually ran out at about 20 kts below the slat retract speed, leaving the aircraft ' hanging' in ISA +15 air and very reluctant to accelerate. A very long practically level segment was required to get up to clean climb speed. The system was not used extensively and was soon withdrawn, as a water injection pump failure left a tank of water on board which could freeze at altitude.
While I can still remember:
T1 full tanks: 13680 kgs
T2 full tanks including fin fuel 23040kgs
T2 full tanks without fin fuel 21809 kgs.