I fired an AR at our club one day that had an "entry" size stock on it. They are made for situations in which you're wearing body armor. If that's not the case, you'll find it nearly unusable because it will be too short for you unless your arms are shorter than normal.
This is a personal observation obviously.. none of us are built the same nor do we have the exact same placement of our heads on the stock.. if you shoot nose to charging handle, you will generally find shorter stocks more comfortable. If you are use to using optics with a longer eye relief then you'll not find them comfortable on average.
Hence the multi-positional M4 and CAR stocks which are the dominant configuration for AR's.
With regard to the shorty ACE Skeleton Entry stock.. they're durable and a tad heavy, but you and butt-stroke a bastard with one and they're gonna know they got tagged on top of you're highly unlikely to bend the buffer tube like you would with a typical M4/CAR stock.
Look at the SOCOM M4 standard stock as another option. Less snag potential and they are way comfortable at about the same weight as the M4/CAR stocks. Add to that the Wack a' Fool option (heavy serration on the bottom of the stock body) and it's one of the best out there.