That relative 'fact' is easily countered by the fact that the graphics of MTW look like a streaming pile of plop. Literally. Not to mention twice the cultures, twice the factions, twice the diversity in units, etc.

Buy RTW.
Yes, we know MTW has twice the cultures and unit diversity, and the graphics are not as good, but having re-installed it and played it again, it is a much more enjoyable game than RTW is AT THE MOMENT.
Rome has a lot of potential, but for me, the most important factor of FUN isn't there.
I am about to lose as the Poles in a High GA game to the damn Almohads. They own half of Europe (literally), it is going to be impossible for me to beat them, but I will try.
There has never been this much sense of 'hopeless fun' in RTW.
MTW has it's drawbacks yes, but it is fun to play, which for me, graphics or no, is the most important thing.