I've recently bought a JV1010 and I've also tried an XP30. I've noticed a
couple of things that I would share with you and I'd like that people
more expert in Roland synths give me their opinin about it.
1) The JV1010 has a very disappointing technical problem. When I use the
bank knob in category browsing mode and I switch between patches in
different categories while playing the module it stops reacting to
incoming midi messages. I have to restart it to make it work again! It
doesn't happen always but rather often (in an hour of auditon of the
patches it happened to me 2 or 3 times). It is not a problem of my unit
because I also tried the demo rack in the music shop and it react in the
same way of mine.
2) The XP30 sounds worser than the JV1010 and have different presets.
Moreover patches with the same name sound different. It is strange to me
because Roland says that the two modules have the same sound engine….
Please tell me if you have the same problem with the JV1010 and if you
have noticed the same difference between JV1010 and XP30. Thanks,

I have the same problem as what you're having, Lorenz. I don't know if it is the JV1010 or my controller. I tried it with any keyboard (not Roland) and it did the same thing, losing midi signal when you switch to a different banks. I have to turn off the module and turn it back on again. I am thinking about getting a Roland controller because Roland module doesn't sound good with any keyboard (older keyboard like DX7)other than Roland. Does anybody have a similar problem using JV101 with Roland controller?