So far I have enjoyed the SRT feature on my 46xv545u. Would I say I am blown away by it..no probably not, but it is a nice added feature. First of all I will say the native upscaler in the TV is already pretty good, as good as I have seen and I was impressed with it when I saw my SD channels as I was very worried about them. So put SRT on top of that and you have yourself a TV with probably about as good as SD will look on a HD TV.
It obviously isn't going to do miracles on 480 material so don't expect "near HD quality" with that particular input quality. But I think it does good enough of a job that it would put this tv above most others out there in terms of SD quality. It definitely does better with certain feeds over others (I just mean some 480 feeds are better than others). You will see a difference when you turn it on and off. With the correct settings I think it bring just enough enhancement in without going into the too sharp range. Another example would be with my Wii. The picture is pretty good without srt, but with srt on it gives it just enough enhancement to make it look damn good and make it pop.
I think one of the keys to getting nice results with this (and one of a couple things I bet the cnet fellas didn't do) is to turn down the regular sharpness and let srt do the work. SRT does a better job than the regular sharpness, so you don't want to put one on top of another. This is somewhat of a bummer if you like your sharpness higher with your HD channels, because then you would have to adjust it all the time. However, I just find a happy medium and set my sharpness like 15-20, so it provides for not oversharpening the SD channels and giving just a bit to the HD channels. Personally I like mode 2 with a level of 2-3. As long as my sharpness is low, I usually go with the level at 3. I wouldn't recommend anything above 3, because even if the sharpness is low and you start to go in the 4-5 level range as it starts to get too messy/jaggy (again this is regarding 480 input from SD channels, regular dvd you may be able to get away with a higher level).
Honestly I can't give much of a review on SRT with dvd's I really only tested it once and it seems to do a as good job if not better than my panny bd35 player. Without testing it more it is hard to say, but I would probably lean toward the srt because you have more options to adjust the scaling to how you like it. Its nice to have the extra option of choosing what I want to do my upscaling. The panny will just scale with no adjustment. I still need to try it against my AVR254's scaling, but I have a feeling srt would beat it as well.
So overall its a good feature, I am glad to have it. I don't think I would solely buy a TV just because it had this feature, especially if you think you are going to get HD quality out of SD channels. But fortunately Toshiba xv's have an excellent PQ with HD and its a great value. So with the added srt to give you nice SD, it makes it a steal!