I haven't seen Dr Spunj's spreadsheet (I can't open the file), but built a very simplified version based off a summary of it. I'm currently running a pbp game using it here, and the players seemed to be pleased enough with the results.
The characters fall between PC and NPC in terms of 'power'. You can't get everything a PC has class has in terms of the number feats and abilities, but you can get what you want.
After using it, I now find the class system a bit of a pain.