This article is from the Breast Pumps FAQ, by firstname.lastname@example.org (Beth Weiss) with numerous contributions by others.
There are no absolute answers to a question like this. Some women
have been very successful with every available pump. For just about
any pump, you can find some women who think it was great, and others
who weren't successful with it.
Many lactation consultants recommend electric pumps (either the "fish
tank" pumps or the rental pumps) for women who are returning to work
full-time, or pumping for a premature baby. The following is a
compilation of women's comments about various pumps. Since this FAQ
file originated several years ago, please understand that any and all
prices are likely to be out of date.