Yes, being able to read a Skew-T is still important
IF
you want to do a reasonably accurate job of Forecasting for cross country or competitive flights.
IF
all you want to do is fly around the airport, or decide to make instructional flights, looking at the pretty colors is good enough.
Why?
Well XC Skies only generates the pretty colors every three hours. That makes it pretty hard to predict the beginning, and end of the day with reasonable accuracy. Model Update times on the sites with pretty colors lag what's available directly from http://rucsoundings.noaa.gov/. If you make an early morning forecast on the east coast, update time is important, and having one available every hour is important if you want to know when to launch and when to land. Model selection...All the models are lying to you, too some degree. The question is which one of them is lying to you the least? The most reliable model for this air mass, today, may not be available on the sites with the pretty colors.
I have not tried Topmeteo, but plan on doing so this spring. If the only model it uses is the NAM, we may have problems with it on the east coast. On the day of the flight the NAM is not your usual best choice of weather model to look at. Its pretty much all you have looking three days out (along with the GFS), but it's not known to be all that accurate for this afternoon.

Looking at the pretty colors is better than doing nothing, combine that with a quick look at the satellites for clouds, and the mixing height, and winds on the NOAA tabular forecast, and you will have something reasonably OK.



SF