I have demo'd the projector in question and it was great, it's from a reputible person.
Only potential issue is 20 months or so warranty on the used vs 36 months on new. On something costing more than £1400 makes me twitchy!
Then again the machine is proven with no problems at 16 months old, kind of like a car, you know it should be ok if any major issues were going to surface they'd have hopefully done so by now...