Acrylic is a great choice, especially for CA residents. Acrylic stucco is essentially an exterior grade paint mixed with acrylic and crushed quartz. This is just to give you an idea of what it is like, the material itself. It is rubber like and minimizes cracking a lot better than conventional stucco. Lahabra is a stucco company that makes conventional stucco, that's who your particular contractor uses as a supplier, so he simply calls it a 'LaHabra Coat'. It is white cement that has the sand added to it already and you achieve custom colors by adding 'color packs' to the white cement. This finish uses different materials, so it will have different textures than the acrylic finish. It does crack easier, but not much. Akrotique is a system of modeling the acrylic stucco's color. After the acrylic stucco is applied, a water based color or colors are added to the wall to give it a more 'modeled look'. I love this finish. In the end, if price is not a factor, then I would go with acrylic. It is more durable, more customizable and shows less cracking (assuming the stucco was applied correctly). It can be painted later on, just be sure that the paint is suited for acrylic like the stucco is. Really though, this stuff lasts a long time.....20 years or more before even considering painting it. A re-coat would be better than painting it too and SHOULD only cost a little bit more. Hope this clears up any questions you have. Here is a link that might be useful: http://www.thestuccoguy.com

Houseful, If they go over the old stucco, not only will you never see what damage and leaks etc might need to be repaired - well maybe in theory the new stucco will protect it - your walls are going to get really thick. You might need to replace or extend window sills/flashings etc, since if they become recessed in the stucco, water will get behind them. Not good. I think the only way to get a satisfactory result would be to remove old stucco. I've done it, not fun. Mind you I dislike stucco from that point of view anyway :) Just because these guys SAY they can do it that way, doesn't make it so. Ask to see previous examples of this redo, and ask the owners how it's held up.

Contact the place where they sell the stucco and ask or go to see bigger samples. When I was choosing the color of stucco (different brand), my contractor sent me to the store where he purchases his supplies and they had 2 walls of displays of stucco brands by color including la Habra. I was able to take a few samples home to look at them at different time of the day/light. When I finally narrowed to 2 options my contractor made 2 big samples which we placed against the walls on construction site and finally made a decision. With stucco colors it is really tricky. It changes color depending on the time of the day and light. In certain lights you can notice hues which you cannot see other times. Above is the picture of the stucco sample made by my contractor.

The stucco should be removed. While it might work, it might not, and Hardie may not warrant the installation.