Product review (5 stars): it seals and drains better and no longer retains water
I replaced this because ours was the original and was retaining water and getting kind of moldy. Our washer does not have the lower drain however this gasket appears that it can work with either model as it has all of the different style plugs on top and bottom; they're just filled in so you cut out a hole for whatever ones you want to use. Now that we have a new gasket, it seals and drains better and no longer retains water.

As far as the spring clamps: there are two but only the front clamp should need to be replaced (part #2W20017E). Our front one was all rusted out but the rear looked perfect. I did not buy the spring clamp tool and instead loop zip ties through each end of the spring and pulled it apart to get it on and off. Getting them off was easy but it was a pain to get them back on. I could't do it myself and needed my wife to help. I think overall it took about an hour to change.