Lets just hit the major points:-E3D hot ends specify 3Nm torque for nozzle installation, this is typically no problem. (I do this a lot) The Olsson Ruby comes with no torque spec, or any instructions packet, only instructions are written on the inside of the box and say “excessive force may cause damage.” Nozzle twisted straight off at less than 1Nm, about an inch pound if I were guessing. (we use a torque wrench, in inch pounds, because we’re cautious about this sort of thing)-Didn’t even thread until it seated on the heat break before twisting off, it broke THAT EASILY (no it didn’t bottom out). This was it’s saving grace, because it meant the heat break could simply unscrewed in an attempt to salvage the heat block.-Screw installation, if you did successfully coax one one of these nozzles in, after some use how would you ever get the torque to REMOVE one of these? Throw away your whole heat block and heat break?-Nozzle isn’t solid, uses a free-spinning internal brass tube, which will impair thermal conductivity, and will be abraded by the hot molten filament.-The “ruby” head has no taper or flare or anything, it is flat and square. This means two things: 1) the abrasive filament is still going to be eating away at the soft brass nozzle insides (obviously) and 2) that filament is going to pile up behind the ruby and have to all somehow find its way out. Back pressure much? Also, anyone who knows about injection moulding knows this is particularly ugly when you’re trying to move fibers.-Square shoulder will also make cleaning the nozzle when switching filaments tons of fun, because garbage will collect at the hard corners here.And since everyone loves pictures, we’ve got a nice album (no particular image order). Gives you a look at the down and dirty inside one of these things. http://ift.tt/2hi2OqK that was informative. If anyone has any question, hit me. :)UPDATEBought this nozzle from Matterhackers. They were prompt in their reply and said that the nozzle indeed appeared to be defective and offered me a refund or replacement (opted for refund obviously), but went the extra mile and offered to replace the ruined heaterblock as well. I thought that was darn swell of them, but declined the replacement heater block because the nozzle isn’t their fault after all. http://ift.tt/2yneikN