What I have heard is that the Hydros does feel a bit stiffer than the Helios, not because of differences in the blank, but because unlike the Helios it doesn't have the flexible Recoil guides. The stiffer guides stiffen the whole rod just a bit. I have cast them both (and bought the Hydros as mentioned above), but not at the same time so I couldn't do a close comparison. All I can say is they felt similar.