Don't work for Dassault there in LBG do you
jr of dallas?
Seriously though. LR45s had a problem with their APUs but that has been resolved. HS125 can be difficult to work on but you need a good engineer no matter which aircraft you get. HS125, you replace a valve/pipe. 45 it's generally replace a "magic box".
Can't comment on the DA50.
Good luck,
Chips