Rhetorical question - Sell off or Keep (Generally speaking)

Hello Gents,

I just recently bought a pair of Kef LS50s (which I'm Luvin BTW).
So now I have a pair of Dynaudio Emit 20s sitting the floor in the back of the room.
I originally planned to upgrade to the Dynaudio Special 40s (another story all together).

I have nothing at all against the Dynaudio Emit 20s other than in my situation, the Kefs seem to be providing the next level of performance I was looking for. 

I haven't swapped in the Dyns since I have connected in the Kefs, could be partially a honeymoon period I get that. 

So the real question is -  Keep the Dyns (As a backup pair) or part ways and move on.  
I don't have another room I could create for the Dyns so I imagine they will be mainly idle. 

In the past I've parted ways when upgrading however this time I'm still trying to sort this one out.
Anyway I realize there are different schools of thought on this topic. Just curious what's your M.O. when upgrading.

Thanks,

Doug