Fireful0,
Bruce hit it on the head, as usual!
All three (or four if you are me with the one-off Guitar Ace Blaster prototype!) are decent amp simulators. Period. But that's it. They won't replace an X100 for that patented Rockman sound (no CLEAN 2 and no spacial effects).
Def Leppard used the Guitar Ace to record Hysteria and guitarist Phil Collen had SR&D custom build him an XPR with the Metal Ace distortion circuit. But both he and the dead guy supposedly recorded one string at a time so the sound is probably more attributable to Mutt Lange's mixing in the studio. Regardless, he or the not dead guy replacement no longer use them live or in the studio so...
I actually prefer the Bass Ace to the Bass Rockman for recording. It has more UMPHHH!!! I find the Bass Rockman to sound great through headphones but difficult to remix the preset EQ settings to POP in the mix when I record.
Hope that helps! And let me know if you need a nice, replacement X100... I can make that happen!
Very respectfully,
Sunburst