Star San is designed to foam and is recommended for running in foamers. That can be problematic in enclosed CIP situations where a lot of foam can be hard to rinse. Most iodaphors pose a similar problem but, from my experience, to a somewhat lesser degree, and some are available in low foaming versions. Peroxyacetic acid type sanitizers are generally non foaming as are Chlorine Dioxides. Personally, I still like iodophors for their broad kill spectrum and versatility. On the downside, they tend to turn all your rubber and plastic parts yellow and I don't recommend for no-rinse.
One other thing about star san - I used it for a while and found that it was very hard on soft rubbers like Buna. Especially when used for parts soak buckets, it caused all my gaskets to swell up to the point that they were unusable.
Free State Brewing Co.