Are you asking if Gridseed is a trusty company or if minereu is.
If asking if Gridseed is, I would say yes, as I purchased 2 of them. And they work as promised. I have never used minereu, so can't say anything about them. I personally use
http://www.gawminers.com/ and can say they ship out very quickly, and have a good reputation. For that price, I would almost suggest something like this. Since it will give you a bit more mining power for your money.
Yeah the KNC's are going to destroy everything, but my question is, how many are actually going to be sold?? I have no doubt that LTC difficulty is going to go through the roof, and will no longer be able to be mined by small/mid level miners, but there are enough different coins out there, that there more that likely won't be a few KNC's (or even 1) sitting on them. The profits are def not going to be there though in the short term, so I wouldn't be thinking of the miner paying for itself quickly (or possibly ever). So as others were saying, the safe bet is buying coin now and not mining them.