I have to agree with 1337, but for different reasons. The paint colors in those combination kits are frequently the "Basic" colors or colors that you will never use. Just get the colors that you need for the model you are working on, and after a few models you'll have accumulated enough different colors.
The putty,as mentioned, is not that great either. I use Squadron putty for general purpose gap filling, or just gap-filling super glue for the minor gaps.
For glue I prefer cyanoacrylate since it dries so quickly. Specifically I like Zap and have been using it for many years.
The plastic cover is OK, but a plastic trash bag works just as well and can even be used for trash when you get tired of looking at the paint spills on it!