Some trade-offs to consider in ergonomics and size.. some pros and cons. - NcSTAR Mark III Tactical Series 3-9x42mm Rifle Scopes

I purchased this with the intent to mount it on a flat top AR style rifle. When I opened the box upon receipt, I could tell that I had been sent someone else's return item. (thanks Optics Planet..) The plastic bags on the box and on the scope inside were torn open and then sort of wadded back together and badly taped. Sigh. I examined the scope, it seemed otherwise unused except for the adjustment screw on the quick release mechanism which had the screwdriver slot bunged up and damaged, apparently by the previous owner trying to turn it without loosening the locking nut first. I am still deciding on whether to return it for refund.
Aside from that, here are my impressions of the scope:
I feel that this is a well made sight with several good useful features for the money. I paid about $90 including shipping. The two different reticle illuminations (blue and green) with three brightness settings work well. It arrived with a battery installed and a spare also included in the box. The scope reticle (I bought the Mil-dot) works fine without the illumination as well. The scope is clear, bright and sharp. The 42mm objective end brings in a lot of light, the variable zoom action is smooth.
So far so good, BUT, this wanna-be ACOG looking scope has some drawbacks. The description did not give the dimensions of the scope, but it turns out it is pretty big. It measures 7.75" long (19.8cm) which is the SAME LENGTH as THE ENTIRE UPPER RECEIVER. So, it does NOT allow the use of back-up folding rear sights because the long eyepiece end extends over that area of the rail. Even if you could mount a folding sight, it would be unusable without removing the scope. The quick release mechanism works adequately well, but it is not an elegant design, particularly the small adjustment screw and lock nut and stamped steel sliding plate are all a low budget design, but this IS a low budget scope so fair enough. The biggest problem I find is the eye relief length of JUST THREE INCHES. Three inches is the distance your eyeball must be from the eyepiece of the scope in order to see the entire field of view. To do that requires an unnatural and uncomfortable forward cheek weld position when shouldering the rifle to sight through the scope. Even mounting the scope on the upper receiver rail as far rearward as possible it is an awkward sighting arraignment. Also, the long scope may interfere with easy access to the charging handle especially if you have big fingers. If your rifle has a standard front sight frame, it will extend halfway into the sight picture in the scope as a blurry blob. That is not the fault of the scope, just something to be aware of when planning your optic choice.
I was disappointed that this low cost scope did not fit my expectations better.