Take my thoughts with a grain of salt because I have limited experience with the ORX and even less experience with the Deus (I own both and have 3 coils).
The ORX is the lightest weight, easiest to swing, detector I've ever handled. It lacks the numerous options that the Deus has, but the general performance is equal (or very, very, close). Very good in the iron. I mean unbelievably good. The ORX comes with 4 programs and the ability to save 2 "custom" programs (but you cannot name them). Two are labeled coin programs (Fast and Deep) and the other two programs are labeled "gold" programs (Gold and Fine Gold). The ORX is limited to 3 tones - with no option of changing the number of tones or the tone breaks. The ORX can be balanced to salt and does quite well on salt sand (including wet salt sand).
The headphones (XP calls them backphones) are very good. I cannot discern any lag and the performance is very good in my opinion. The ORX pairs with the MI6 pin-pointer as well - so you hear the pin-pointer in your headphones when the MI6 is turned on. It is a feature that I love and I am very pleased with the MI6 as well. The MI6 can be adjusted through the ORX remote (once the two are paired).
The ORX would not be my first choice for hunting in a lot of modern trash. It loves aluminum - and with the inability to set tone breaks a lot of aluminum trash sounds very much like a coin. That all but forces the user to pay close attention to the VID numbers on the remote. I believe part of the "problem" is that the ORX normalizes VDI numbers (no matter the frequency chosen) to those numbers for 18 khz - bunching higher conductive targets into a fairly small grouping [of numbers].
The ORX also lacks a depth meter - although you can get a rough idea of depth when using the pin-point mode. Deeper targets (or small targets) will give off a weaker tone, but I haven't figured out at what depth that starts (still working on figuring that out).
Pinpoint mode is a bit different [from most machines] - once entered you must press the 'back' button to exit pinpoint mode. Not a big deal, but it still doesn't seem natural to me. I usually "pinpoint" by tightly swinging the coil as I move it back from the target. When the target is no longer heard, it is at the very tip of the coil.
I tend to hunt old permissions that have a lot of iron - bits and pieces of square nails, farm equipment, etc.. For those types of areas the ORX is fantastic. I have dug a number of coins (and other desirable targets) that were co-located with multiple pieces of iron (mostly nails, wire, etc..). I always hunt with iron audio on - but seldom pass on a target that gives an iron tone as long as I can get a consistent high tone (even if it is only in one direction). That's because there is so much iron (bits/pieces) in my permissions that having iron (in the same hole) is the norm.
I am very happy with my ORX and believe the expense to be well worth it. I am still in the process of learning it, but see no reason why my approval (of the ORX) would change over time. If anything I suspect I will appreciate the ORX even more as I learn it more thoroughly.