The Panasonic S60 is a good basic plasma. Its blacks are really impressive for the price. However, it reflects a lot of light and it doesn’t get very bright, so it is definitely not suitable for a room with windows.
You will notice a lot reflections as soon as you turn on the lights. Combine this with the fact that it can't get very bright and you will not see anything in a bright room. If you plan on watching it during the day, go for the ST60 instead (it has good anti-glare).
It is a little bit less of an issue when watching bright content.