The viewing angle isn't anything special, but it's fine for me, don't plan on spending much time viewing it at an angle, the sd card slot and hdmi out are it's main selling features for me, although thanks acer limitations, apps can't be moved to the sd card :/
Over all I'm very please with it, the price wasn't bad either, $200CND on sale, vs $239 or $269CND for the nexus 7 16GB or 32GB respectively. As far as I can tell the only major difference between the two is the lower quality of the screen and screen resolution, the storage space, the addition of HDMI out on the a110, and 4.2 on the Nexus 7 vs 4.1.1 on the a110. The a110's processor is slightly slower, clocking at 1.2GHz where the Nexus 7 makes 1.3GHz, but the difference is negligible.
If I were forced to comment on which is better, all I could say is it depends on your preference, for me, the expandable memory (which once there's a root for the device will become infinitely more useful) and HDMI out sold me on the a110. If you need the nicer display and the quickest OS updates however, then the Nexus 7 is what your after. As far as I'm concerned, on a 7" display, the a110 looks fine to me, but there is a noticeable difference.
As far as the tv output goes, I have not tried it yet, but I will be back later to comment on it's output resolution.