I'm in the "keep it simple" camp. I use Excel, have a column for each attribute that is important to me, and can sort it however I want. Can easily prepare a sorted report for taking to a meet to make sure I don't accidentally buy something I already have.
If your inventory system lists a "total value", I strongly suggest protecting it from the significant other with a password. 
What a person should use depends on what functionality is important to them. Personally, I'd rather spend my train time working on the layout or running trains.
