Read abit.
In summary, Reiss who was the founder from Londinium used to remark that Strega was a disaster and levers don't work without using thermosyphon heating control and a pump. Then he later made the Londonium R which he claimed to have a lot of remarkable improvements, also does not have the thermosyphon system and has a pump.
Strega has a microswitch actuator to control the pump at will to fill the chamber as you like. Meaning you can extract from 3 to iirc 10 bars pressure as you please. Londonium R iirc works slightly different in this, there's another pressure switch that set at 3 bars to stop the pump, so you can't experiment as much or as freely with different pressure, which has a direct impact to how it transform the flavours. From this, it's already quite unfair for the Londonium to really compete heads on. Some also remark that back to back extraction on the Londonium have heating stability issues, especially in the original older designs which were mostly designed for plumb in.
Last is the Londonium, needs a full hour to heat up. You won't want to let it on 24/7 because of power consumption and the electrical parts have a lifespan. There's zero local support and all help must be obtained from Londinium directly, so you must DIY do all the repairs and servicing.
The Londinium used to look more awesome with the wooden handles, but that is now also available on the Stregas. Not easy to get the Strega, my colleague wanted to get one last yr but it was always oos.