I don´t want to spoil the XT 4pot-party - but the new XT is technically identical to the current Saint and also the ZEE.
The calipers are identical, except for the machining/finish/color. The masters are identical to SLX on the ZEE, XTR on the Saint and XT to the XT M8000 2piston system.
And oil/fluid volumes, leverage rate and all that is exactly the same on all three brakes. If you use the same pads and rotors, you won´t be able to tell any difference in performance, because they perform the same.
You could discern a minimal weight difference, because of the master cylinders. And you don´t get tool free reach adjust on the ZEE. You can combine almost any Shimano master/caliper combination and have a reliable, working brake. Most of them are just the same three variations with different finishes and color/logo combination.
I´ve spent the last few seasons on various ZEE and Saint setups and have M8000 XT and SLX brakes on the backup bike, the GF´s bike and so on. At times swapped masters or calipers when someone bent or tore a lever etc.
The only brake that ever acted up are the M8000 XTs. Had a leaky master which was warrantied, seemed to happen a lot with their first batch.
The M8000s (2pot XTs) are a notch better to modulate than the older XTs or the SLX and seem a bit stronger, maybe what you´re looking for.
My girlfriend didn´t like the Saints I put on her bike. She did go over the bars three times (uninjured) and found them "too strong". She doesn´t complain about the M8000 at all. I rode the same M8000s on my Reign for a while and didn´t notice them in a bad way. They were alright even on long steep trails for my 77kg.
If you buy a set which was manufactured after July 2016, you´ll probably have no trouble.
I´d recommend to stick with a ZEE with 180mm rotors though - if they are too grabby with the 200mm rotor for you. I DO feel that the Zees modulate very well.
Or get sintered pads and 200mm Magura rotors for your ZEE.
Sintered pads without cooling fins and NON-icetech rotors are my favorite.
Actually I run Magura STORM HC rotors now - they are 2mm compared to Shimanos 1.8mm. NO noise, less vibration, no warp when hot and they last longer and are cheaper, also more braking surface for lots of bite.
And I personally wouldn´t run any SRAM/AVID brake with DOT anymore. I´ve had several Elixirs, had two sets of Guides (RSC and RC) and even though the lever shape is nice, after the second or third pad swap, they are toast. Start to leak, need constant re-bleeding, don´t offer tons of fade resistance and also not tons of stopping power.
Over here they are even more expensive. After warranty replacement I took em off my bikes, sold them to some avid lover and bought cheaper Shimanos. No going back.