A final Trangia word: they sell a "winter attachment" for their spirit burner that is intended for priming said burner from underneath in harsh winter conditions, when the meths or bioethanol might otherwise not catch light readily. Primed underneath with a couple of drops of bioethanol (and that's all it needs at room temperature), the time that the burner takes to boil a pint of water drops from eight minutes to less than six, including priming time. Surprisingly fast for such an unsophisticated piece of equipment and faster than the Trangia X2 multifuel stove burning pressurised Coleman Fuel (at risk to life and limb).
Here is a summary of the boiling times in minutes for various permutations in ascending order:
Kenwood electric kettle (on the 240V mains) 1.3
Trangia gas burner, Coleman gas cartridge 3.0
Trangia X2 multifuel, Aspen 4, Omnidawg silent cap, 37mm jet 3.1*
Trangia X2 multifuel, Coleman gas cartridge, Omnidawg silent cap, 45mm jet 3.4
Trangia X2 multifuel, Coleman gas cartridge, Omnidawg silent cap, 37mm jet 3.5
Trangia X2 multifuel, Coleman gas cartridge, 32mm jet 3.8
Trangia X2 multifuel, Aspen 4, 32mm jet 4.9*
Trangia spirit burner bioethanol, winter attachment 5.9
Trangia X2 multifuel, Coleman Fuel, 32mm jet 6.5*
Trangia spirit burner, bioethanol 7.9
Trangia spirit burner, meths 8.0
Esbit spirit burner, bioethanol 8.5
Esbit spirit burner, meths 10.0
* Does not include priming or burning off time (to remove remaining fuel from the system and to depressurise it), both of which take about two minutes