hi...
... i am not an engineer,
but there are not many differences:
@ fuel:
PATS tanks, 2 tanks with 900kg capacity each, located left and right fwd of cargo compartement, cargo compartment slightly smaller than "normal" CRJ
fuel deliverd to PATS tanks via centre tank only, lots of gravity and x-flow lines....
2 extra fuel panels in flightdeck
@ water system
most cl850īs have a front galley and toilet, pilots and mechanics (and off course pilots) should be aware of the slightly complicated draining procedure
@ airshow
have not seen any crj with an airshow computer..
@ differences LH and midcoast
be aware, that there are some differences in midcoast and lufthansa 850s..
eg: midcoast has a different potable water refilling system, (and only one single point aftward refilling) whereas LH 850s use the standard crj refillers, back and fwd.
electric system, lighting etc..., expect different systems on midc. and lh aircrafts
i am sure, there are some more differences.., but all in all it is the same aircraft.
for further feel free to pm
welle