lol you kinda took everything out of that equation by getting laterial G's.. anyways, motion rigs... suck.. lol its not that they are bad, they are extremely well thought out and whatnot, but its still .. not near what it is supposed to do, its impossible to "make" that many effects act through just a few hydrolic pistons, you have vertical G's and lateral G's.. thats 2 aspects, some companys dont do such a good job with those even at that, as for the fact that the forces are acting on you the entire time.. all a machine would do is just maybe tilt you sideways or something, but you still wouldnt be experiencing but a miniscule amount of lateral G's for only a few milliseconds
and then beyond the basics.. you still have however many more forces that .. i dont know yet so i cant tell you lol
as this is one of the things that falls under the categories of "yes.. it is impossible to recreate something real"