The quad rail is nice as I don't think any of the old ones had a full quad rail maybe 1 did with a suppressor. Stock looks an improvement over the originals as well at first glance much better space for batteries.
A mate of mine has a couple of Specna M4's that his kids use. Despite much abuse both continue to perform very well. Several folk I know have got them and all rate them.
I don't know what's improved with the 2.0 version but I can certainly recommend the older EDGE series. My SA-E03 shoots brilliantly and also has quad rails.
@EDcase does it have rail covers? Missed that when I was looking at them.
One thing I will say about the SA-E12 I have worked on is that the stock bucking isn't fit for UK FPS or weather. Much too stiff until it heats up but it does make sense they swap the spring from 370+~ fps to 300~ fps the bucking would need to be stiff at that speed.
@L3wisD still 2 s-mags in the box with the H series?