P4 2.53 GHz
1280 MB RDRAM (1066 MHz)
256 MB Radeon X1600 Pro
The BBS feature has a problem where, when I tell it to download new BBS levels, it pegs my CPU at 100% until it's finished.  It seems like this happens when the program is just sitting there waiting for data from the server, however I suppose it could also be because some Rube Goldberg algorithm is being used to process the list of levels.
The editor is basically unusable, due to lag/slowdown.  If the editor has different system requirements than the game itself, could these be posted?  People like me with old computers would appreciate knowing this before buying the game ;)
I've encountered these issues in multiple versions of the game.  Both seem to occur in v0.1.6, but I don't remember which previous versions I noticed either/both of them occurring in.  They both did occur in at least one other recent version, though!
Just to make sure I'm clear: the actual downloading works fine.  The issue is that I really would appreciate it if Voxatron didn't hog all my CPU when it's sitting there waiting for the list of levels or whatever.  And yes, I know it's alpha and everything, but I couldn't find anyone else who had reported this so I thought I'd try and be helpful :)