Have been tinkering with it.  It looks pretty cool.  It has dual-pane functionality, which it didn't in the past.
I'm also an xplorer2 user.  I'd guess that the above (pro) version of XYplorer is more powerful than the Lite version of xplorer2, but the paid (pro) version of x2 is more powerful than the pro version of XY.  Price-wise I think that XY retails for $70 (I don't know what the upgrade policy is).  x2 is $40, but an additional $30 if you want the free lifetime upgrades--hence the prices are similar.    Anyhoo...  Other folks may evaluate the comparisons differently, but no matter which meets your needs better, you can't beat the GAOTD price of $0.   ;)

My thought with going 'portable' is that since all of the files and such would be in the Dropbox folder (and not in the Registry, etc) then the app could be used on different computers.  The way I'm imagining this, however, I think you could only have one computer running at a time--AND Dropbox would have to fully sync before CHS opened.    I find that I am now having problems with the second requirement.  Sometimes my work computer takes a while to get online, and sometimes Dropbox is blocked altogether--which makes my use-across-both-computers system not feasible. 

Regarding 'databases' in general; I'm not a programmer, but I think it is possible for an app to share a database, but only it it was designed to do so.  For example FileMakerPro or Microsoft Access can have multiple users simultaneously working on the same database.    The application just has to make sure that each file (in this case, each clip) in the database has a unique ID #.   Also, if a file is already in use by another user, then it can only be opened as "read only."

I'm not sure how all of this would apply to CHS, or if it would even be possible.  I guess each clip would need to be locked by default, as soon as it's captured.  If you wanted to edit a clip, CHS would try to unlock it (and only be able to do so if it's not already unlocked by another user/computer.)  But what would happen if you browse to the folder that contains the captured PNGs??  Would those also be locked?  IDK.