Idolmaster has time going for it... It also was built from the ground up, from an arcade game to a console release to a game series to an anime and movie. Love live and aikatsu, and even cinderella girls were the same way... Meanwhile WUG was basically expected to transform into a huge franchise overnight. And it didn't.
Plus (and this is my opinion) WUG made me feel unclean... It goes so far to show how the idol business is screwed up beyond belief, yet it still wants you to buy into said idol culture. It blasts fanservice as skeevy and gross but doesn't hesitate to show you shots of the girls' panties or them in swimsuits, though it does get better. Plus watching a show that kind of hates you isn't fun.
Plus I feel like all of them are for different demographics. Love Live is for the K-On crowd (I feel a lot of similarities, especially with the school vs. office setting); aikatsu is for young girls and the precure crowd with the idealized and fluffy setting, idolmaster is idolmaster, and WUG is sort of... Out doing its own thing.
Although in terms of music...
WUG (I have every I-1 song on my iPod) = idolmaster > aikatsu >>>>> Love Live
In terms of cast personalities:
idolmaster > love live > WUG > aikatsu
In animation and character designs:
love live = idolmaster (I like im@s' designs the most, but I don't like the anime's art style, it's the opposite for love live) > aikatsu (kind of generic animation-wise but with cute designs) = WUG (the animation is legendarily bad but it boasts my favorite art style out of the group)
In terms of how much I enjoyed them:
idolmaster > love live = aikatsu > WUG