I only got BF4 2 days ago but it's good enough for me to probably not bother playing Ghosts for a while, don't get me wrong I don't think Ghosts is a bad game but BF4 is far better.
I haven't suffered any problems with Ghosts or BF4 regarding frame rate problems, crashes, loss of connections etc so I think I've been lucky.
I might revisit Ghosts when the DLC drops as that should generate a bit more interest for me.