Ideal mid-range detector off the top of my head:
Balanced like the Fisher F75 - With a well balanced machine, weight is almost a secondary consideration. The F75 weighs a half pound more than the AT Pro/Max but you do not feel it. Light Weight like the Deus is a bonus.
Compact Travel Mode like the Deus
Long-lived, rechargeable, user replaceable batteries various manufacturers
Built-in Wireless Headphone Capability using bluetooth standard and waterproof wired capability like Minelab (Garrett is close but uses a proprietary wireless headphone protocol)
User Interface like the Fisher F75 - Simple, easy to read and navigate. One button, one knob.
Simple, Intuitive, Effective Grab and Go Mode like Tesoro. Simple enough for a beginner to grasp, effective enough for an experienced detectorist to not be left wanting.
Submersible like the Garrett AT series, Minelab, Whites (don't need a dive machine, though)
Recovery Speed Fast like the Tesoros and Deus and Variable Like the Deus
Multiple Tone Choices like the Deus (2 - 5 tones, "Full" tones, and pitch)
Stable, Accurate Target ID (visual and tone) at Depth like Minelab
True All Metal Mode implemented like Whites (MXT) and Tesoro and like the Teknetics Patriot Series/Fisher F70, perhaps now with the AT Max, not sure.
Wide Range Multifrequency Modes Like the Deus
Simultaneous Multifrequency like Minelab Equinox
Very High Frequency Prospecting Modes like Minelab, Deus
Firmware Upgradeable Like Deus, Nokta, Minelab
Cell Phone Integration and Program Uploading Like Minelab, Deus (though none can upload custom programs to the controller that I am aware of). Note - I am NOT looking to replace the controller with the a cell phone. I need a standalone controller as the primary user interface.
Wide Variety of OEM and 3rd Party Coil Choices like most brands, though I think First Texas has the best variety and performance of OEM coils.
Super High End Model would have FBS multifrequency mode and PI modes available - lol.
Add things I forgot, throw darts. Give the OP information he should consider for his ideal mid-level machine.
Looking at all of the above, the Equinox comes pretty close to fitting the bill vs. the Max.