The Vanguard was one of the fastest propellor commercial aeroplanes ever built. Its block times on domestic services were very similar to Tridents and 757s due to its ability to use the first intersection it came to - and turn off the north r/w at LHR straight on to the alpha stands.
LATCC had to post a notice to controllers - "Notice that Vanguards descend at the same speeds as jets" after a couple of embarrassing incidents when they had tried to get 737s through the big V's level on the gounds that they were faster.
The faster she went the more precise became the handling - with only tab-assisted controls in lieu of hydraulics. Allegedly a Vickers test pilot wote that, above 400k IAS, he preferred the Vanguard to the Valiant!
Service Vne 330k at low level.