I have had 2 Medela pumps, an inexpensive battery operated model and an expensive model that plugs in, does both breasts at once, and does it pain free. 

There is no comparison.

Go for the big ones!  Most of my working mom friends have Medela pumps, and all of the models are great.  They are expensive to start with, but te batteries cheaper pumps require add up quickly.  And cheap pumps HURT!

Medela pumps have several controls to set the pump to imitate your own baby's suckling strength and speed.  It is very convienient, having it's own carrying bag and it is laid out very nicely.  It's...