Tudor black bay case size differences

[cdog]

Just stopped by an AD in Lahaina earlier today and ended up checking out some Black Bays, one with the ETA movement and one with the in house movement. In comparing the two, it appeared that the case back on the in house movement protruded out more than the ETA, to the point that the watch felt less balanced on the wrist. Both cases appeared to be the same, the difference being in the case back thickness. Has anyone else observed this and if so, has it effected comfort in wear?