Mark you cant have it both ways... you said "Looks are deceiving...Latest X3 isn't much smaller these days" and you said "X3 proportions look weird" and then you said "go for a used X5" (which is the same size as a new X3).
If you want a X5 get one but the X3 is not so different in size or shape to be worth worrying about. Purchase and running cost and engine size are much more significant.
BMW X3 (F25) xDrive20d SE . . Alpine White. . Oyster Leather . . 8 Speed Servotronic. .RFTs. . High Beam Assist. . Electric Seats . . DAB Radio. .USB/Bluetooth