First time I can hear it. I have MR200 from 11 months and my friends use MR200 too and everything is OK. I'm afraid that people says a stupidities about MR200.

I don't know what you mean with " I'm afraid that people says a stupidities about MR200.". My MR200 killed my sim-cards. Twice. That's a facts. Others have this problem too. Your unit does not have this problem. Fine. But that doesn't make my problem go away.

So ether
a) there are some faulty MR200 units out there. I got one. An exchange of my MR200 may help.
or
b) there are some (modern?) SIM-cards which get killed after some time if used in the MR200. Which means that an exchange of the MR200 will not help. I'm quite sure my mobile provider is using state of the art SIM-cards. Newest model. The one with NFC support for mobile payment. The MR200 is "older". Maybe there is a compatibility issue?

If I go with a) there is a risk that the new unit will have the same problem.So I probably will go with b), send the MR200 back as "faulty" and the another router (maybe from another brand). Any suggestions for a LTE router with good LTE reception and 5ghz wifi?

Hi, do you have a test with other SIM card? My SIM card can work well with MR200. Do you insert and pull out your sim card offten?

No, i do not pull out the card. It is a dedicated sim card in a dedicated router. 7x24 online, in one fixed place, servicing the whole building (LAN + WiFi via the MR 200 + WiFi via another router). About 20 devices. I installed the router and the (brand new, never before used) sim card back in December, and it worked perfectly from day one without any service interruption or any reboot for two month. Then there were 2 days with problems (router was offline with sim error, reboot helped for a day), after that: sim card was not recognized any longer. After replacing the sim card with a new one, all was back to normal. I just removed the destroyed sim card, put in the new one and the router was back online. Not even a reboot was required. Well, for two months, then I needed another sim card. Same story: Two days with problems, then a dead sim card. I replaced the sim card another time - back to normal. I do expect good service for another two months, and a dead sim card in June.

The destroyed sim card seams to be physically destroyed - at least it is not recognized by an other device (i tried smartphones, tablets).