Avent Double Pump

TnG05

Hi all, 

I'm curious if anyone here uses the Avent double pump and your overall thoughts on it.  I've been using one for about 4 months now and I'm not sure it was the best pump since it doesn't seem to get out as much milk as I think it should.  I'm considering getting a new pump but my son is 7 months old now and I'm not sure it'll be worth it.  I plan on bf'd and/or pumping as long as my body produces milk but of course I don't know how long that'll be. 

Does anyone have any tips besides hand compression while pumping to get the most out of this pump?  

Thanks.