I listened to the Stelloa and LCD-XC side by side. Don’t get me wrong, I liked that fat bottom end subbass Sound from the XC, it was a fun listen and put a smile on my face, but every song sounded the same with them, very „fat“, like listening in a car with a build in subwoofer that is always „on“. The Stellia on the other hand shows the music (more or less) as it is. I am coming from flat/neutral IEMs (ProPhile8) and am considering upgrading to the stellias because it is clearly a step up. So it depends what you want. XC is very fun and if I had the money I would listen to the one or other EDM album with them, but if you want to hear unspoiled mids you better save for the Stellias. Alas I don’t know about leakage of the Stellia. I was alone listening to them. But the clamping force is not really tight (very comfortable) so I guess there is leakage when listening with higher volumes.