Would my ps4 system be good if I have my ps3 super slim system on top of it

[starmask2k3]

I would like to put my ps3 super slim system on top of my ps4 system to save space would it be a good idea to do it

 

[Dramatic Crysis]

I've been doing it since the release. I've had no issues whatsoever. 

 

[starmask2k3]

Thanks are they both on at the same time