I'll go with Iron Maiden.

art: I like the Alice Cooper cabinet and backglass much more, but I find the playfield for Maiden more pro looking and it integrates a lot of themes within the actual pinball layout (look at the Eddie in the padding room between the pops!), and it's actually about the band in the title. In the meanwhile, Alice's one looks more like a poster than a playfield to me, the castle is very cool thought. Overall, I like Maiden's better.

layout: let's just say Iron Maiden is the winner here.

sound: I'll put aside the music as there's a lot of personal taste here, but from the little gameplay I saw from Alice Cooper, it sounds like Iron Maiden takes the cake here with 2 voices full of energy doing the call outs and awesome sound effects.

gameplay: I really need to see more Alice, but from the Iron Maiden stream I saw today... man, that game is fast and fun! Alice seems like an orbit that you can chain with another orbit, and despair. I really need to see more Alice's gameplay to be sure, but from the layout and what I saw I reckon I'm not that hopeful.

or... you could go for an IRM and in 6-8 months just look for someone selling/trading his/her ACNC.

Right, Alice has the castle mini playfield where you can shot at what seems like 4-5 more shoots.
In Maiden however, while there isn't a second level playfield, you have different shots that can be done only with the extra flippers, which there are 2 pointing in different directions, what in a way make different levels. Add that you can chain the shots between these levels and that is fun, and actual flow... which is different than flow in a single orbit or between ramps, which you can do too. Add to that rules that allow to stack modes and you have plenty to shot at non stop.

could you expand on this? like, what are you considering to arrive to this conclusion?

yeah, pretty hard.

do you mean to say that stereo adds tonality?

I understand what you mean by "one mic at one speaker", I had broken headphones before. I don't think THAT has anything to do with tonality, and if you fail to understand the difference then there's really no point in arguing. Not that I want to argue really, there never was nothing to argue: stereo don't change tonality (that is a fact) and tonality is my ... observation.

I have to say I'm glad that, for you, being in front of it makes it so much better.