I can't help with yur first two questions... I haven't heard of a "new and improved" version, but there always will be the next best thing as soon as you pull out your wallet on the old, obsolete, stupid phone/pad/computer/car/TV/wife....
As far as screen protector/film... I don't use it on the M and have had no issue. I'm not particularly gentle, but mostly keep it in my shirt pocket away from keys, etc. I never used one on the DINC either, and it held up well for nearly 3 years.