All 3 are nice. What is your pool made of, plaster or vinyl liner?
I have the Oasis z5 and its an awesome machine. Doesn't have all the bells and whistles of setting a program or waterline only, but it is fast and has a strong pump. It also comes with a 3 year warranty. You can get it from epic pool supply for $1049 and use the coupon code poolreview25 for an extra $25 off. Then you get a $50 rebate as well. Ends up costing you $975. The Oasis comes with a caddy and remote.
As far as Active, I would get the Active 30i from
Home | Marina Pool Spa & Patio They are selling it for $899 with caddy and it has bluetooth. Its a lighter unit and it filters a little less water. It has the bells and whistles like scheduling and telling the cleaner to do waterline only, floor only or floor and waterline. It has a 2 year warranty. When buying from Marina, you have to call them to order instead of ordering online. That unit can't be sold on the internet. Its a great price though. By me, that unit is $1300.
The premier is a nice unit but it doesn't come with a remote or caddy. Also, the filters are on the bottom, which can be a little annoying. There are also a lot of reviews that say because its on the bottom, some dirt comes back out when lifting it out of the water. The equivalent to that would be the M400 from marina pool. That unit has same motor, split brushes, caddy and remote and 3 year warranty. Difference between that and the premier is the split brushes and top loading filter. Marina pool supply is selling that one for $999 (its the 2016 model) so it doesn't have bluetooth, but a remote instead. (which I like better). The 2016 m400 is the same exact unit as the Oasis z5. So if you are thinking of this route, save the $25 and go with the Oasis
Personally for me, the warranty is worth the extra $75 between the active 30i and the Oasis. The Oasis is a strong unit as well. IMHO, the warranty is more important than the bells and whistles. I know people leave these units in the water all the time, and the manufacturer says you can, thus the programing feature, but I don't and don't suggest it. Ive spoken with a lot of owner and all the people who have issues with them, leave them in the water. You have a plastic unit in Chlorinated water. Eventually, the gaskets will break down and water will get into the unit. Probably right at the end of the warranty. Thats just my opinion and 2 cents though.