Do not expect any excitement or anything spectacular. The steps are filled with tourists and vendors selling tourist-y stuff. My suggestion is you will appreciate the steps more if you happen to "stumble upon" it while shopping near the area, instead of deliberately making a trip there.

The steps are a nice spot to sit and relax. I guess people climb them, but we were too lazy. The fountain at the bottom is actually prettier and more interesting. This whole area is crawling with people all the time. If you are travelling with a lovely lady, the flower vendors will come up and give her flowers, then beg you for money. We fell for it once, and then a second vendor tried the same trick! Stop by if you are in the area, but check out the whole neighborhood, it's more interesting.

Beautiful piece of architecture and a carnival like atmosphere with sketch artists and people selling wares. Also a nice place to sit and people watch if you don't mind the sun. Of course it is gross to see a McDonald's at the food of the steps but shutter your eyes as you walk by it.

Saw the spanish steps and agree that it is a very nice vista, but nothing on the colosseum or some of the other attractions in Rome.
Still it is at the top of one of the most famous shopping streets in Rome, and I guess that combination is reasonably special.