I have both CADPAT and Multicam. My CADPAT is what sees most use, as I live in eastern Ontario, and it seems to work best. In spring when there's no foliage, it does make me stand out in the woods, but otherwise, it works best for this area.
I haven't worn my multicam yet, but every game I've played to date, I've been playing on the "green team". So from my perspective of shooting at people with Multicam, I don't find it horribly effective in this area except in fall or when playing in open fields in summer with tall, dry grass. Multicam then blends right in. In summer though, Multicam stands out quite a bit for me, even with having partial colour blindness.
But Multicam looks very cool, and I plan on using my MC loadout mostly when playing indoors anyway, so I don't really care about its camo properties.