This is a new monitor line from Acer, to replace the one where S231HL and S211HL are featured.
If you compare this S232HL with the older S231HL, then you'll notice that this new S232HL monitor is missing VESA Mount holes, so you won't be able to use this with stuff like Tyke Supply Dual Monitor desk clamp.
Acer also has a mess regarding the specs of this new monitor: some of their literature claims an improvement from 5ms to 2ms for the 23" model, and also from 170°/160° to 176°/170°. However, other docs claim that refresh rates and viewing angles are identical. Supposedly, this new model is slightly thinner; however, the previous model was already terribly thin, and without putting them side by side, I'd say they don't appear to have different thickness levels. This new version seems to address the annoying uber-bright power button from S2x1HL, which is a nice improvement.
Unless you're into gaming, really hate the prior power button, or this monitor sells up cheap, I'd recommend you stick with the prior model that has VESA Mount and is currently considerably cheaper than this new model.