Have had both units for a few days and have tested them out and figured I'd report my "findings" for any who might be interested.
First to Doctego,
The Vizio sound bar is taller than the Sony. I haven't measured, but the Sony would definitely fit into that space. I'm pretty sure you can take the feet off the Vizio but I can't vouch for how well it would sit without those feet. Actually, my guess would be not well, as the cables plug "up" into the soundbar. My HDMI was very thick and I had to take extra effort to bend the cable so that it wasn't pushing the soundbar forward, because there wasn't much clearance. I also had a thinner cable which wasn't a problem, but if you took those feet off, I'm not sure you'd have enough clearance to run the cables. I guess it would depend on the cable.
Second, and I don't know if this would really matter for your situation, if you want to hang the sound bar, to avoid potentional cable issues, it's not simplistic to do so. I've read other posts where people have done it, but there are no holes on the back specifically for this purpose. There are holders designed to work with the wall mounts supplied with the unit, but as far as I could tell, you can't remove those holders so I'm not sure how you would hang it, or mount it above the TV for that matter. The Sony unit had holes on the back which would make it much easier to hang from the TV.
Truth be told, I liked the look of the Vizio a little bit better ... it's a nice looking and sounding unit.
Hope this helps a little bit.
Ramoer was correct ... I had missed extensively testing the various SRS modes. When I went back and re-looked at that, it started sounding much better. Very good, in fact. There is a setting labelled TruVol. I really don't know exactly what it does, but it solved the problems I had indicated above and really sounded good when I turned it on. To my ears and my wife's, it sounded better than the Sony unit. I could hear some effects in my test movie (Lord of the Rings pt 1) that I couldn't hear in the Sony unless the volume was much higher. (In fairness, I was still trying to figure out what settings worked best for the Sony, but it was an obvious difference.) My guess (untrained & uneducated guess) is that the TruVol enhanced the audio track in some way. Most of the time it sounded better than the Sony. However, in the end, I decided to stick with the Sony. The difference was in the "most of the time" previous comment. Throughout my testing, 4 or 5 times the sound dropped out completely for a second or so. I don't know if my unit was defective, or maybe there was some interference with the wireless subwoofer, or maybe that's just the way it's supposed to work. I really don't know, but I didn't care to spend tons of time trying to figure something out that I wasn't even sure could be figured out. Second, there were occassions when the sound would not drop out completely, but would .... just change in sound. It happened consistently at one point in the movie, when the sound would suddenly drop to half of the volume and then build back up over the next few seconds. Again, I don't really know why this was, but my uneducated guess was that the enhancing algorithm (or whatever) just had trouble with that particular spot. My first guess was that it was just the soundtrack on the DVD. However, this did not happen on the Sony unit, so that's why I think it had something to do with the way the Vizio enhanced the sound. When I used the Sony, I wouldn't call the sound spectaculr, but I would call it rock-solid consistent. I never heard changes in level like I would occasionally with the Vizio. It didn't sound as good, but it also didn't distract me when those little, admittedly probably minor, variations in sound did occur. And while it wasn't an easy decision, for me, in the end I decided a good consistent sound was preferable to a better inconsistent sound.
Don't get me wrong ... I'm not suggesting the Vizio was *bad* in any regard, but these little things were noticeable and I thought that over time it would distract and aggrivate me and I'd rather have the Sony unit which never seemed to get in the way or distract me from what I was watching/listening to. Perhaps my unit was defective. To be honest, I didn't want the hassle of going through another one to see if indeed that was the case. Also, I'm still trying to figure out the ideal balance for the Sony unit, so given a bit more time, I think I can make it sound even better for what I'm looking for. I really was conflicted because I really liked the sound of the Vizio better. But, in the end, I chose the "good" and consistent sound of the Sony. For what I spent, less than $200, it is a nice improvement over the TV speakers. I'm sure for a lot more money you could get something that would blow the Sony HT-CT150 out of the water. But, I'm not willing to spend that kind of money, so am happy with my compromise.
Hope this is helpful to somebody.