I've used my Lightspeed Zulu in a number of different Robinsons, and am very happy with it. It's comfortable and clear. I have run into a particular R22 which didn't work with one ANR and one basic, training school standard non-ANR (same behavior with a Bose or LS ANR), but was fine with 2 ANRs. I've also seen an R22 which refused to work with any ANRs at all, in any combination. I suspect this is more an audio system thing than an R22 thing.