Hi Al,
I certainly wouldn't call myself a style creation expert ( haahaa) stylenut is more like it.
As far as the keyboards go, I can't comment on the Roland, I haven't owned one in years.

For onboard style creation / editing functions, the PA800 leaves my psr lagging behind..
Apart from realtime recording functions which they both have (& I'm not musical enough to use)
They both have the ability to copy a style track from one style to another ie copy a bass track , or a drum track from 8beat 1 to 8beat 2, thereby with this mix n match method, you can create some interesting new styles without a great deal of effort.

The pA800 can copy a complete style part
( not just a track )ie a variation or intro etc to another style. Not sure if my psr can, but the same result can be acheived by copying individual tracks across, just takes longer.

The PA800 has the ability of importing & exporting a style part as a midifle to an external sequencer.
Where I'm finding this handy at the moment is for converting psr styles into PA800 styles & editing the drums.
Where possible I try & avoid using EMC for converting my psr styles.Quite often it really messes up the drum conversion & the minor Intro's & Endings of the style.. Instead I turn the psr style into a midifile, Powertrack Pro 12 splits the drum & percussion into individual tracks. I can then edit the velocity of these tracks & transpose them so the correct drum instruments are playing. I then use the import function in the PA to create the style parts.
Another thing the import smf function can be used for is to create new intro's & endings for styles.
ie if I happened to find a really good intro in one of my midifiles & I wanted to incorporate it into a style, I'd just load it into my sequencer, delete the additional song parts, make sure all the tracks are on the correct midi channels & import it into a style.

One other neat feature is I can copy a pad into a style.
How I'd use this is, it's far easier to create a pad than it is a whole style.
So if I find an interesting guitar track, or piano track just say a set of piano arpeggio's in one of my old psr styles.
turn the style into a midifile. Delete all the other data, Save the arpeggio as a midifile, import it into a pad.
Now I can audition the pad with numerous onboard styles. If I find some styles that the arpeggio pads work well with, I can copy them into the style itself, thereby basically creating a new style of sorts, especially if I also change the intro.
I did this with one of the onboard Bequine styles. Deleted existing guitar & bass & replaced it with tracks from a psr Bequine including an Intro & Ending.

Probably most of this stuff can be done on the earlier PA's also, I don't know as the last one I owned goes back to the i2.
A lot of this stuff can also be done for psr styles , but via external software like OMB, Jorgens Midi2 style, Michaels Stylemaker software.

One thing my psr definately can't do is play drum audio loops ie I can create pads & drum & percussion style tracks from audio files that sync perfectly with a style. Haven't bothered with many just a few jazz brush drum swishes. Midi brush swishes don't compare with audio.

Sorry Al, you did ask haahaa

best wishes
Rikki
By the way I've got at least a couple orso more styles for your forum, I'll send them later today.