It's Sigur Ros!
To start, this review is coming from someone who has spent countless hours listening to Sigur Ros and other post-rock bands.
About what the guy below me said about the buildup being too slow, I would have to disagree. In the post-rock world (even though this is a computer-generated mix, you seem to be willing to keep the post-rock theme), too slow of a buildup is 9+ minutes. If anyone wants proof, go listen to Ara Batur (on the album Med sud i eyrum vid spilum endalaust). 7 minutes of buildup where nothing musically spectacular happens, and is still one of the best songs ever created. The buildup is fine (too short if anything). Maybe it could use a buildup to where a slight bass or synth is introduced at around 1:10 (just hypothetically) or so, and then have it's exposion at 2:15 or so (once again, I kind of randomly came up with it). Anyways, enough about the buildup.
Now about the repetitiveness. In order to keep this song from getting too repetetive, you must keep making subtle changes that in time become big changes that lead to explosions of delightful sound, keeping the same melody (about the 4 minute mark of Milano). Anyways, basically what I'm saying is that the repetitive melody is fine, although you must have the instruments around the melody be going somewhere. Of course, without the amazing 'hopelandic' singing of sigur ros, this will be difficult.
Also, something to consider would be (since this a computer-generated mix) to at some point change the melody into a synth of some kind. I'm not sure it would work, but it certainly is something that is worth experimenting with. Also, you could try layering the melody with one deeper reverberating synth while you have another more 'pingy?' cheerful trancy synth.
Now to the beat. I'm not really sure what to do about it. I mean, it sounds fine as it is, but it's not spectacular. In the original Milano, the use of cymbals is really what drives the song into euphoria. It would sound less techo-y that way, and I'm not sure if that's what you want, but anyway, just something to think about.
Well, that's my best attempt at just throwing out some things for you to think about. Throw away the crap in this review, and keep whatever you think is a good idea. Making a mix of anything Sigur Ros is certainly a task to be reckoned with. Good luck with this and the rest of your music!