I've tried a few different pumps, both electric and manual. For electric, I've tried the Ameda Purely Yours (hated it) and the Medela Pump In Style (better but still hated it). For manual, I tried Medela Harmony (loved it) and then the Lansinoh Momma (LOOOOOVED it).
With the Ameda Purely Yours, the suction was either too much or too little and I could spend 30 minutes per side and only get like 1.5 to 2 ounces. It was painful and beyond frustrating. Essentially the same thing happened with the Medela Pump In Style. I couldn't control the speed or vary it as needed which was no good.
The manual pumps worked WAY better for me, and specifically the Lansinoh Momma I found to be even better and way easier to assemble and clean than the Medela Harmony. I pump at work and the manual is easy to disassemble and carry in a bag in my purse. You also don't have to keep buying replacement membranes like you do for the Medela pumps so that's a HUGE plus, I can't tell you how many times I went to pump with the Medela and stressed out because the membrane I was using looked like it might be wearing out, or broke, or I couldn't remember with my foggy mommy brain where the heck I put the bag of replacement membranes etc. etc. etc.
So all in all Lansinoh is the most effective, cheapest, easiest to maintain and most convenient, in my opinion! Don't spend $300. Electric pumps suck in my opinion and NOT in a good way