I don't think that the mixing has redused throw, ie half speed.
I use it for my planes and I think it has the same amount of movement as normal.
You could always buy a dx5e and get a mixer as well if this is the problem or....
Buy a ESC with a built in mixer eg Sabertooth, SyRen, Scorpian.
You could go for the DX6i which is very nice but the dx5e is still very good.
I use a planet T5 with a sabertooth, which has built in mixing. This is almost the same as the spektrum but the planet, unlike the spektrum, doesn't have a failsafe.