So I did bunch of messing around with stock Hippos themselves & swapping the Hippo stems with other switches last night. With some successes & some failures, unfortunately nothing really stood out of the pack substantially IMO. With the one exception being Tescee Blue Velvets, the Gateron PE stems felt lovely in them! Although in my testing Invyr V1 PE stems felt even better.
In fact my first experiment with the Hippos was to put an Invyr V1 PE stem in one & compare it to a stock one. The one with the Invyr stem was noticeably smoother. That & the yellowish color of the Gateron PE stems makes me believe Gateron went super light with the PE used in the mix for the stems. Don’t get me wrong they are very nice switches as is & will probably really shine with a proper lube job.They are definitely a decent bit smoother than Gateron KS-3s with POM stems. Although they fall pretty short on delivering the ultra smoothness good PE stems are known for IMO. Here is the combos I tried last night & some thoughts on them. (stock Hippo always on left in these pics)
Pic comparing the color of the Hippo stems & Invyr V1 stems. I popped an Invyr V1 into a Hippos housing & they were decently smoother. One of the reasons I think Gateron is not using much UHWMPE in the mix for their stems.
Decided to try a Hippo stem in a regular black Gateron KS-3 housing. Surprisingly they felt less smooth in them & the yellow stem felt smoother in the Hippos housing. Makes me think Gateron has retooled their KS-3 molds. Now might be a good time to stock up on regular KS-3s of your prefered flavor.
Swapped with Red Inks. Nothing special all feel pretty much equally smooth, but the PE stem takes away from Ink’s coveted deep sound signature.
Swapped with NOS vint MX blacks. Gateron PE stem to tight for Cherry housings, NOS vint black stem felt good in Hippos housing, but wobbled more & wasn’t smoother than the stock stem.
Swapped with Tescee Blue Velvets. These are the standouts as the Gateron PE stems felt extremely smooth in the Tescee PME housings! Although if you can get some Invyr V1 PE stems they feel even smoother so still not really a viable mod IMO. Also Blue Velvet stems felt noticeably scratchier in the Hippos housings.
Swapped with Snow Whites. The Gateron PE was too tight for the Snow White housings, but the Snow white stems felt very smooth in thew Hippo housings. Almost as smooth as the stock PE stems.
Swapped with FFFF linears. The Gateron PE stems felt pretty smooth in FFFF housings, again though good Invyr V1 stems are smoother. Then the FFFF stems felt very good in the Hippos housing, pretty close to the stock stem TBH. I think the fact Durock/JWK has been polishing their stems is what accounts for this & Snow White stems feeling good in the Hippo housings.
In a normal Gateron milky top/black bottom housing. Nothing special, the PE stem feel scratchier in them. No counter comparaison cause the milky top housing came from Gateron browns.
Swapped with KK Lightwave V2s. Nothing special, PE stem feels roughly just as smooth as the stock stem in the Lightwaves. Plus makes the sound worse. The Lightwave stems in Hippos housings has the same effects.
Swapped with Aqua Kings. Again nothing special, you’d be hard pressed to figure out which is which in a blind test. Both feel pretty much the same same with either stem.
Swapped with V1 Alpacas. Same story as Aqua Kings, but with more wobble on both examples.
I still have to give them a try in Durock POMs & NK Creams to see how they react with all POM housings, but I’m doubtful it’ll be anything impressive. All in all my big takeaway is that Gateron has kept the amount UHWMPE to a minimum in the mix for the stems as other aftermarket UHWMPE stems perform better. I’m thinking Gateron did this to keep QC under control & minimize the amount of rejects so I can’t blame them. I’d definitely recommend Hippos as they are a good switch overall, but don’t expect anything beyond a slightly improved Gateron KS-3 variant.
Pics of stock Hippo parts below