Agreed, it's a fantastic preamp.  I'm a happy owner of a stock F360.  Would you care to comment on the improvements the Jupiter caps and Z-foil resistors made?  I've definitely contemplated some upgrades, but have a hard time choosing from all the options.  Caps would definitely be on the list, and while I do love the sound of Jupiter copper foils, I've also enjoyed the V-Cap ODAM and Miflex copper foils I've had in different components too.  Can't go wrong with any of them, IMO, but they do bring different strengths to the table.  
GLWS!