I have wedding cake steps and really like most things about them. I still have a couple kids that can't touch bottom and this is a good place for them to hang out when they are playing. I have not had trouble with them harboring algae. The steps I have are Majestic 8000 ( you can see a picture on Amazon). I find the weighted sand tube in the steps incredibly difficult to remove when it's time to pull the steps out of the pool and even though it hasn't been a problem in 3 seasons, I have concerns about the arm that attaches the steps to the pool deck. I worry that I'm going to bend or break it when I install the steps. My pool deck is under the top rail. If your pool deck is above the top rail, this set up will work much better.
You really need to take them out and clean under them weekly. I drain the water from my weights weekly and use a little algeacide in the weights. Weights are leaning on the railing in the pic. I Get new stones every year now and pre-wash the stones in slam water. I have added more holes and plan to add more this year.