We bought this cot when our son was around 6 months old, for putting up when we stayed the night at friends and, we hoped, trips abroad. This cot has since been an indespensible part of our travel kit, whether we are spending the night at granny's or going to India or the US for 2 weeks. Our son is almost 2 years old, and still uses the cot.
It is extremely light and portable. Will fit inside a suitcase, or can be slung over your shoulder as carry on. The first time putting it up i had to follow the instructions, but now we can put it up easily in about 2-3 mins.
The cot itself affords the child a lot of space. I have seen references to tying down or tethering this cot. We have never had to do this. I suppose if your child was to stand up and grab the sides and start shaking it it may be necessary. But the way the cot is designed (with all the area distributed at the bottom) means it is extremely unlikely to topple (in fact, i can't see that happening at all). I suppose at worst it may move across the room if the child was particularly aggro.
The mattress is not the thickest in the world. We often put a folded sheet under the cot to give some more comfort/protect from cold floors. This is fine however, as such items are always available and I'd rather not carry that bulk in the cot when we travel.
In short, I am really glad I purchased this instead of a heavier, solid-style travel cot. It has done the trick for us with minimum fuss. As I said in the title, this has been one of our top baby buys. I have certainly spent twice as much on things I have used a tenth as much. Not sure what age it is rated to, but our son is going on 22 months and I can see us using this for a while yet.