These bowls are great. I almost got the set with 4 bowls, but I'm glad I didn't as I think the smallest bowl would have potentially been too small. These bowls are very nicely sized.
I like that it is very easy to store these. Simply put the lids on each bowl and next them inside each other. Do make sure they are dry though if you do this as the lids seal extremely well. I've had covered mixing bowls before and they've always sealed like crap. I'm very pleased with how these seal.
These are of course easy to clean. They are easy to use a hand mixer in. They have a variety of very useful sizes for your needs.
I'm very pleased with these items. I don't think I'd recommend putting the lids in the dishwasher in the long term though as I think it could screw up how well the lids seal. The bowls themselves could easily go into the dishwasher though.