LDG AT 1000Pro 2. or MFJ 998 to use in the mobile with Yeasu FT450D

Of the two units which one would work best in a mobile with the Yeasu FT450D. The ATU would be used after my amp.
FT450D, Amp, ATU, Antenna.
This install will be in my new 2014 ram 1500 pick up, and will be used mobile...
I like the LDG, but it looks like the MFJ will "tune" lower on the fly were as the LDG looks like you can set de falt swr but 1.7 is where it want s to be ???
Thank you.