I was also someone who went and bought MTW after having played Rome. So I think I can give you some information.
The Graphics will need some getting used to, at first I was so turned off by them I simply auto resolved all the battles, and even put down the game for a while. Also, for your first game play the English. Not some civil-war prone faction Like the Holy Roman Empire - I had to learn this the hard way.
Once you're able to look past the graphics, and learn how to work with the left click select - and left click move- controls you're ready to start playing the game for what it is. You'll start appreciating how important it is to not simply attack everyone when you feel like it, but to make alliances and tech up carefully before attacking. You'll find out that all the things said concerning MTW are quite frankly all true, however, you'll have to see for yourself if you like MTW better than you did Rome.
At the moment I'm enjoying a Turkish early campaign using the MTW XL mod, and a RTRPE PBM campaign - so yes, you can combine the two.
And have a good time playing them both.

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