nginx is an amazing piece of software. Light, fast, and as everyone mentions it holds out pretty well against abuse. I use it on my dedicated server to run several websites (mostly hosted for others) that do pick up a bit of traffic running forums. The box itself is often under heavy load, and Apache would start to grind to a halt with the load the machine is under.
The connection limit is for being a good netizen. While there are standards, you can enable pipelining which helps more than spawning a boatload of connections as you go. Just remember, more connections results in more server load and more overhead on your network and the server, so use it in moderation. Some servers are aggressive with the amount of connections they allow as well, and will firewall you if you spawn too many in a short amount of time.