Thank you all for the responses. That covers things nicely.

The comment about ease of use is interesting; I always like devices that can be operated with one finger whilst the house is burning down! Some years ago this was the main reason I bought a Yamaha MU80 rather than a Korg X5DR mobule; i.e. I could operate it without the manual. Of course, having been hooked into XG by the MU80 is the reason that I find myself here today.
It's just a pity the Ensoniq SD1 I use as a Master keyboard doesn't understand bank changes in the XG/GS sense!