Like many great blends, this one is attuned to the particular pipe it is being smoked in at the time. When smoked in an old Castello, I use for Latakia-based blends, I get a dry (non-sweet) smoke with a rather unpleasant finish on the palate. In a meerschaum the sweetness appears, the smoke is cooler and the burn is slower. In several other Latakia-based briars, London Mixture performs well with a basic "English Blend" flavor.
I did not find anything particularly interesting or outstanding with London Mixture. Being an ancient blend in a current climate of continually evolving tobaccos, London Mixture is no longer the proverbial Leader of the Pack. There are far more interesting English blends out there today with similar price point and better availability. I doubt I will be purchasing another tin of London Mixture but I would recommend it for someone starting on English blends or for a mild all-day "no-brainer" smoke.