JDJones,
If your looking at "ease of loading", the 270 AM kicks the heck out of the 7mm AM for the level of performance you will get.
The 7mm AM will drive a 200 gr ULD RBBT to 3200 fps, the 270 AM will drive a 169.5 gr ULD RBBT to 3350 fps and some are pushing 3400 fps.
I will say there is more to be had with the 7mm AM but we have to work on bullets that will handle the strains of this round. So far we have proven that 3300 fps is possible with a 200 gr bullet but at these velocities, extraction gets a bit sticky and the rotational strains are a bit much for the 200 gr ULD RBBT.
I am testing other twist rates right now to try to find a combination that will allow this round to run full tilt with good bullet performance. Seems the 1-7 may be more then we need for the 200 gr ULD RBBT but when the 225 and 250 gr pills get here it will be very useful.
The 270 AM is so easy to load for and very high in performance so its hard to beat to be honest, especially in a Rem 700 based rifle, very easy to build a 270 AM in this receiver.
With the soon to be released 185 gr ULD RBBT for the 270 AM I suspect it will produce velocities in the 3150 to 3200 fps which will nearly match the 7mm AM ballistically. Terminally, the heavier bullet will be packing more energy and penetrate deeper in the 7mm but both will be amazing to say the least.
The main advantage of the 7mm AM is what you are calling a disadvantage, that being the Lapua cases. Very strong, very high quality.
Its really a personal preference, if your looking for ease of loading in one of the Allen Magnums, the 270 AM is head and shoulders better then all the rest if thats the only thing your looking at comparing the rounds.
Good Shooting!!
Kirby Allen(50)