We have both Houdini and AFMr. Houdini has been in the house maybe 1.3 yrs. AFMr, just a few months. Despite AMFr being ranked #2 (and for good reasons), wife's favorite pin is still Houdini.
Both are fun to shoot in their own right. But that's really where the comparison ends. No doubt, Houdini has a lot more going on and more challenging shots. AFMr is a faster paced game - lot's of easy targets to hit. Who doesn't like nailing the saucer over and over. Houdini, you need to really think about what you need to shoot and when. But that is where it shines if your in the mood for that style. And at times it's just as fast and furious as AFMr.
But to pick one over the other is really hard - they just play so different. To the point I wanted them both. Some days I'm in a mood for an easy game and Houdini just sits there. Other days I want more of a challenge and Houdini gets the play time while AFMr is ignored.
I'd mostly ignore all the 'bricked' shots Houdini comments. You'll learn the shots. In easy mode it is very forgiving - lots of second/3rd chances. But on route, I wouldn't think Houdini would fair very well since there is a learning curve. AFMr is a no brainer for just pressing the start button aiming for the saucer.