I first recall seeing goodwins years ago on ebay, they would get some old clapped out Harrison M series or Colchester, paint it, bolt one of their generic import DROs on it and try and flog it as a "refurbished" machine.
They might be perfectly fine people to deal with, but I always ignored them after seeing that crap.
As far as import DROs go my dad and I bought a 3 axis Sino from China through ebay years ago, before they were readily available in this country, to install on an old Beaver turret mill he had. That was around 15 years ago at this point. It was really a decent bit of kit, the scales were nicely finished and the whole thing was pretty good. He sold that mill a couple of years ago, DRO included. It was still working perfectly at the time. He paid very little for it, I can't recall how much, but somewhere around £300 for the whole kit and caboodle. When they started appearing from UK sellers, the prices were inflated as you would expect.
About a half a dozen or so years ago I bought a DigiMac branded 3 axis unit from I think Poland IIRC, to fit on a little Kearns S type that we use for some second op stuff. The finish on the scales was pretty rough, the reader heads and caps on the ends of the scales were pretty shoddy die cast and I was fairly unimpressed. To it's credit though, it is accurate and has never skipped a beat since I installed it.
I have never bought any from Allendale, but I have a big old Boko F3 here on the waiting list...