Just want to tell everyone who buy a new cup to examine it closely before you use it.
I bought a Meluna M soft a couple of weeks ago and when I had boiled it for 5 minutes and was about to insert it, I discovered a lot of small cracks on the inside of the cup. They were kind of hard to see, I thought they were dust and tried to brush them away at first. Then I realized that this cup would be really hard to clean... I sent an email with a picture to Meluna and they seemed really surprised - so maybe I'm the first person to get cup with that flaw. I'm pretty sure it is something that happened during the production of the cup, but I never got an answer to that suspicion. I can't imagine that something happening to the cup after production would have made that kind of cracks. The other cup I got for free in the same delivery had a perfectly smooth surface.
Of course I got a new cup sent to me at once so no problems there (that's the good thing about all these small companies - in most cases really customer-friendly and fast!). Just saying it's important to check your new cups thoroughly, whichever brand you choose.
Good luck :)