Sharing a catalogue between Mac and PC

Using a trial version of C1 and think I might well make the switch from LR.

Have a couple of queries - I use a desktop PC and a Macbook pro and with LR I just copy the catalogue between the 2 computers via a portable hard drive, with LR its a case of just updating the folder location which is done in a jiffy.
But Im finding in C1 it seems to take an age to do this and when it has it list the same folder multiple times with 2 pictures in it this is rectified if I quit C1 and re -start it.
Is there an easier way to do this? Is it possible to set a file alias on one of the computers?

Also I believe there isn't away to replicate the stacking feature that LR has ?
I do find this very useful for images that I plan to stack or exposure blend, any recommendations on how to do this in C1

Thanks in advance