Well, after thinking about it for a while (read: an hour) I decided to buy the C9 F-104 package.  Kudos to Ramsa for making me aware of this bird.

At first I was a bit skeptical in regards to quality - but as soon as I loaded it up I was mistaken.  I LOVE this thing.  The simulated APU, RAT, failures and all the procedures are exactly what I felt was lacking in the CS package.  The visual model seems slightly more accurate as well.

The flight charactaristics are truer to the real F-104s, meaning you must be fully alert at all times - particularly upon landing - but you already knew that.  My first landing attempt resulted in disaster.  I followed the standard procedures as closely as possible, but as I began to level out just before touchdown, she flipped over to the portside and smacked into the runway.  Compressor stall works just as it should, APC is just about perfect, it's just great all around.

My only beef at the moment is the VC, as it's slightly laggy and the guages aren't lit as in the (totally awesome) 2d view.

In conclusion, it's a very excellent piece of payware.  I recommend it if you want near-total realism - if you just want to zoom around and not have to worry about various failures and limitations, then opt for the CS 104 instead.