Return or wait

Hello and thank you in advance for replying.

I bought mtw2 when they came out and since then I've jumped to mtw3 and currently on mtw4 through warranty. All of my earbuds had issues and now with mtw4 after half a year of use, the anc of the right earbud does a distortion like a white noise when I'm physical active or when I touch the earbud. Problem solved by turning off the anc, probably there's a problem with the mic. Now, do u suggest me to wait and to jump on the mtw5 through warranty or return them now and take the momentum 4?