i have avent manual and double elec pump. both work well for me and i have bf-ing until 1.5yrs to date. no major prob just rubber parts need to be replaced when the suction getting weaker.

if you have budget concern.. for a start, i suggest a good manual pump. u can pump 1side and DL another side at the same time. you will yield more. baby is still the best pump though.

i feel a manual pump is as good as a double elec pump. just that i can "let down" with my avent double elec pump and it save half of the time compared to manual pump.