I really like the foam; after letting my carboys/bottles drain, the foam makes a seal at the top for a long while. When I fill the container, it slowly pushes the foam out; it gives me the assurance that there's no contamination during racking/bottling.
I started brewing with one of these kits. I think they are fantastic. They reduce the barrier to enter brewing significantly. I spent $70 to get the kit and a few extras and it gave me the chance to brew a couple really nice beers.
To the experienced brewer, these kits must seem ridiculous...
I haven't used clarifiers yet but, I did notice a huge improvement in clarity when I added a 20 minute protein rest. I generally get good breaks and I always filter out the trub when transferring to the primary.
Here's a picture of a california common I made using a protein rest. The rest was...