I have been using the SteelSeries Stratus; though I play infrequently, the iOS 10 support seems to have come and gone. I like the idea of the smaller controller (Micro C.T.R.L.i) because I use it travelling with my iPad Mini. But I also use it with my Apple TV so it's not a requirement. I have researched for a couple hours and the reviews seem to suggest the Nimbus is better and might be worth dealing with the larger size, but I'm not convinced because a lot of the bad reviews on the Micro C.T.R.L.i seemed to be idiots who don't understand they're reviewing the product and not the seller or the site. Any suggestions appreciated. Thanks for reading!
Older thread but I have both. Nimbus is the better controller, hands down. The only thing the CTRLi has on it is the built in clip, but the nyko xbox one clip or the imported one recently featured on TouchArcade are both just fine for the purpose. That does make the Nimbus a bit more expensive for having to add the clip but it really is a nicer controller in almost every way.
I've been using a Micro with my 12.9" iPad Pro for a year now, and loving it. Which seems to be a pretty consistent opinion when I've spoken with other owners.