Agree with gas path, they used Real engines.
Speys were used in their Phantom, the BAC.1-11 & Tridents.
Tays just don't make enough noise.
The Poms liked Conways for a number of uses, including some of their very fast warships.
The following quote may be useful:
The Conway, with a thrust of 21500lbs, is used to power the RAF fleet of VC10 long range transport and tanker aircraft.
It was the first by-pass engine to go into service in the World.