That's because the SR-007 is nothing short of awesome and Dan said all the right things.  That being said I must admit to hardly touching the 007 after I got my Omega/007 hybrid.    Now if I could only get a Blue Hawaii to try them on...  
 
There are of course upgrades you could do to the ES-1 such as install a new PSU just for the output stage, fix the filament wiring and add a CCS to the output stage but it would take SP decades to do this if he even could.