Biggest difference you are likely to find in a practical gigging sense is, IMO, with the arranger you get FOUR drum patterns, six fills and some Intro's and Endings per style, with the Juno Stage, you get more of a 'looper' type pattern switching. Nothing set up to build through a song, nothing set up to all relate to each other, precious few fills...

If you use the E60's drums a LOT, you are going to miss this, I think. If you only use one Variation per song, it's not such a big deal (I know the percussion player probably helps a lot)., but if, like most arranger users, you are stepping through the Variations for Verses, Choruses, etc., there isn't really the same degree of functionality on a Juno. Possibly you could program it in, add new patterns, etc., even transfer pattens (via MIDI) from the E60, but this is likely to be a LOT of work...

OTOH, if you have had a trouble free existence with your E60's, it MIGHT be worth trading one (the most used one!) for the Juno and using BOTH at a gig. But I doubt you are going to be that happy with JUST the Juno if you use the E60's drum section much. I use my G70 a lot like you describe, just the drum section and play everything else, and so far, I haven't found anything else like a WS or a Stage keyboard that offers the ease of use and straightforward way of triggering Patterns that an arranger does...