I have been using these flanges for roughly a month now. It's took a bit for my temperamental elastic righty to come around. Now I can't use hard plastic flanges at all as they end up hurting after lot!

I have used them with the Spectra S1, Freemie Liberty II and Pumpables Genie Advanced pumps. I got more response from my Spectra with them than the others. However, I found a video from New Little Life on YouTube that went into the specs of both the Pumpables Genie Advanced and Spectra. She said that both pumps motors are pretty similar and very close in strength. I found this impressive (and so did she apparently) for the Pumpables being a portable pump.

I ended up switching to using the Genie pump instead of the Spectra as the vibration of the Spectra was starting to get a little uncomfortable and annoying.

I think the reason why my girls are responding well to these liquid flanges over all the other flanges I've tried is because it gives them not only suction but the compression that they get while suckling.

I got my husband to help me find as close to the same rhythm and suction/compression he does while suckling. This has been making a difference too.