Interesting, I actually did also have a look at the Fender thing, but as I definitely will not use it through an amp and you indicate G3 is better for FR; did you get the occasion to compare both G3 and Fender Floor on FR and which one did you prefer ? Second hand you can find them between 120-150 Euros here.
The Tech21 RK5 seems to have that extra boost you're missing on the std version BTW. It's a bit out of my price range (don't find a 2nd hand in EU) From the sound samples I came a bit to the same conclusion as you but, well, soundsamples, I sometimes wonder if the samples have not been a bit "pumped up" you know.
I confirm your list of dishonorable items BTW..
Let me back up a bit and say... I am not what you would call a "tone hound"
I have both the G3 and M. Floor. I will occasionally switch them out to try something new, but after a few hours, I always go back to the M. Floor.
It sounds better through my set up at least, which is a power engine type thing I built.
It has a SS power amp with both line and guitar level inputs and a 2-12 "stacked" cab with Texas Heat guitar speakers.
The G3 amp modeling sounds pretty good through it but the drive pedals all have a kinda cocked wah sound, which I believe could have been
easy to compensate for had they added a bass/mid/trb controls to the drive blocks instead of only a tone control.
I mean COME ON!!! Its programmed.... should have been a no brainer!!
The Floor has a pretty decent drive pedal built in with the bass/mid/trb. It is not a super high gain drive tho... I would say prolly a little less that a tube screamer.
The Floor does have its annoying limits tho!!!
There is an fx loop, but it is at the front of the signal chain (right after the guitar input) and CAN NOT be moved!! Bummer!
It only allows ONE instance of an effect. I.e. one amp, one drive, one mod, one delay, and one reverb.
The fx can ONLY be moved about in the chain via the software... a pain, but can be workable with some pre-saved templates.
The drive and the compressor are both on the "stompbox" block, so it's one or the other, never both!! Bummer!
To be honest I don't recall playing the M. Floor though a strict FR, or even headphones now that I think about it... I am sure I am mistaken but nothing comes to mind... weird!
I did hook up the G3 into the FlyRig and it sounded pretty slick through headphones and was a kewl little recording rig (which I suck at!)
But it did not carry over that well to the stage. So I was back on the M. Floor in just a few hours :O
I am just sharing my findings, but I am prolly the LEAST knowledgeable person on here... 95% of the people would prolly
take the FlyRig over either of these other 2 unit every time.
Hope this helped and I hope you find something that works for you.
Let me know if I can be of any more help