Congrats Red, that's awesome! Did you use ohiodad's recipe as-is from the first post of this thread, or Biggben's tweaks to use 55L instead of 80L and 1968 London ESB yeast? Something else? I'm planning on brewing this next weekend.
As brewcat mentioned, it shouldn't produce off-flavors. However it should be noted that if you crash before hitting FG as it sounds like M&J does, there are still fermentable sugars left in the beer. So if you bottle it, you could easily over-carbonate it or end up with a bottle bomb, as that...