Giant ATX vs Escape?
Depends on the actual spec, but both bikes, as you've identified are fairly similar apart from the suspension.
https://www.giant-bicycles.com/us/atx-3
https://www.giant-bicycles.com/us/escape-3
The drivetrain &amp; brakes are almost the same, but the Escape is slightly more road oriented with 700x38mm tyres, whereas the other has 26 or 27.5&quot; x about 53mm (note: 26&quot; is mostly obsolete for quality tyres, etc., so I'd prefer a 27.5&quot; but on a cheap bike like this it probably doesn't matter much).
The highest gear is 48 x 14 on the Escape and 42x14 on the Atx, while low is 28/34 vs. 24/34. If you are on fast road then you might well like the 48x14 over the 42x14, but up a long steep climb or off road you could also use the lower gear.
The suspension on the ATX is one of the cheapest suspension forks around https://www.srsuntour.com/fileadmin/user_upload/Downloads/Consumer/Bike/Exploded%20views/2014/Suspension%20Fork/SF14-M%20Series/SF14-M3030-A-P-27.5-63%2C75-%281%29.PDF
It's just a spring damped by a piece of foam.
I'd consider it a downgrade on no suspension. Generally you can get enough suspension for most things with wide tyres at low pressure - the pneumatic tyres provide compliance with the road. I can ride over potholed roads with 23c tyres, but it's not fun. 38c is fine for potholed tarmac but if I was cycling over steep tracks that were never surfaced, I'd prefer a wider tyre than that. You can change these tyres yourself, but it's possible the fork/frame/brakes wouldn't fit wider tyres, so you'd need to check that. Keep in mind that in countries with good roads, 38c is already far wider than many people use.
Cheap suspension is popular with new cyclists, but experienced cyclists tend to prefer for cheap bikes like those you mention, no suspension, and then much more expensive and sophisticated suspension for actual mountain biking. This is because suspension adds weight, requires servicing, and may absorb your pedalling forces especially with such unsophisticated suspension which is not properly damped.