Dan, you are right about the break/Fill. But that's NOT what you said in your post.
Secondly, the workaround for no Break fill is hit the Break button, wait a beat or so, then hit the Fill button. (when it's on an FC-7 - not an E50 option, although you can do it with MIDI pedals - it's a snap to do). Break/Fill, get it? 

 Plus, that has the advantage of being different for each variation, whereas I think only the Audya has four B/F's, everything else has but the one. Mind you, the Audya has but four fills, to the Roland's six, so one step forward, one step back (but kudos to Ketron for being the first to realize you MIGHT want a different B/F in the chorus from the verse!)...
BTW, all those things you mentioned as being missed on your E50 are available on a G70 (except the MP3 playback), there are still a few new ones floating around here, but a good condition s/h one can be got for roughly $2k+. That would leave you $3000 change from a Ketron.
Oh, and in case you missed it over at R-A.com, there is software over there (the Session Manager) which can batch convert (or just one UPG at a time) ALL your ROM and User styles, and UPG's to any way you want them. Want ALL styles with Pianostyle, or Standard chord recognition? Want the split point default other than C3? Want the keyboard touch default different?
Piece of cake...
If the E50 is floating your audience's boat, imagine how much more floating they would be once you have a great harmonizer, per Part and per drum sound 3 band parametric EQ, stereo aux ins (with an entire MFX multi-effects dedicated to it), 76 of the finest keys made, IMO the best piano sound of ANY arranger... In fact, the very things you miss on the E50. But still $3000 LESS than the Audya.
That's the thing that gets me.
Oh, and of course, you can, with familiarity probably get around on the style editing stuff as well as a Roland... few others here have. I'm only repeating what actual OWNERS have said. I don't NEED to make this stuff up. 

 But the thing that gets me is that the audio drums and guitars are pretty much completely uneditable. You can't change the sound on the snare, can't tune the toms if they clash with the key of the song, you can't EQ the kick. What you hear is what you'll get. Forever. Need the same style, but a different kick pattern, or a different snare placement, forget it.
The very thing that makes the Audya sound awesome (remember, I'm as in love with the SOUND as you are 

) is the very thing that prevents you from changing anything.
Look, don't get me wrong... I would LOVE an Audya  

 But only IF.... It was no more than a PA2Xpro, and the audio features worked as hyped, and there was SOME way to edit audio styles. Heck, if it had everything that makes the Roland's so good (and good enough for you and your audience despite using the cheapest Roland E you could buy!) and THEN added the rest, it MIGHT even be worth $5000 MAP.
But at the moment, it's two steps forward, two steps back (one for the price).
But I can't wait to hear it in your hands... you're a great player, and no doubt your audience will love it too. But will they love it $3750 more than the E50? 
 
 