Yes, TTS basically will read the street address from the screen and turn it to speech. So, it will say, "In 500 ft, turn right onto Main Street". All GPS's I have seen have speech and provide voice prompts, which says, "In 500 ft, turn right". Those units with TTS can say the street name. I like TTS because I think it's safer -- you don't have to look at the screen as much and can pay more attention to the road.
I would definitely prefer the One LE over the One 3rd -- because of the SD slot, it is more expandable. With the SD slot you can download more POIs, maps etc. The main difference is that the One LE has an SD slot and Bluetooth while the 3rd has a live traffic.
Last night I had my TomTom One LE route me to Staples and it was the first time I encountered a problem with the maps. It told me that I had arrived at my destination but it was about 1/4 to 1/2 mile away further down the road. My unit had the 7.05 maps and last night I just upgraded to the 7.10 maps. It would be interesting to see if that fixes the problem.
I didn't try the Map Share feature yet to correct the mistake.
My Magellan doesn't have Staples in it's POI. My Magellan doesn't seem to have individual stores in it's POI -- only shopping centers. So I guess my Magellan and TomTom both aren't perfect but are still great.