Trouble with push fitting diverter in kitchen

My kitchen faucet is suffering from low water pressure intermittently. Essentially, I turn it on, pressure is fine. Turn it off then back on and pressure is almost non-existent. If I then use the side sprayer, it "pops" it loose and pressure is normal again.

After researching it seems to be a common problem with the Pfister unit I have where the valve inside of the diverter either gets stuck or fails. The part is cheap to replace so I got under the sink to take a look yesterday.

Every manual, picture and video I can find for the faucet I have shows a plastic diverter shown here:

http://www.amazon.com/Pfister-9510390-Marielle-Treviso-Diverter/dp/B004PUFJ5C

However, I have this one which is metal:

http://www.amazon.com/gp/product/B0..._m=ATVPDKIKX0DER&pf_rd_r=1R1D3J7GD52MAQNE4830

It appears to work and connect the same but I have no idea why it's there when everything I find shows the plastic one.

At any rate, I tried removing it to see if it is gummed up before buying a new one but I could not get the hoses off. All 3 connections are push-fit. I was able to get the bottom one off but not the other 2. There is not a lot of room but the one I was able to get off I could push in, get the collar down then pull the hose off. The other two though did not want to push in at all so I really couldn't get the collar down to pull them apart. Am I missing something here? I have no idea when this was installed but I would assume 5 years or so ago. Is there a different/better way to remove push-fit connections?