Based on there website the Dually is all that's offered for trout spey (3 & 4 wt) at this time. I've got a 4wt Hydrogen and really like it, never had a chance to try a Dually but I like the look of the cork better. Grain windows look about the same.
The only thing that kept me from buying one was the exposed blank in the reel seat.
I felt the same way about the real seat when I looked at it the first time. Has never been a problem or caused any trouble. I didn't go out looking to buy a Hydrogen spey rod, I took a two day trout spey casting class and we all rigged brand new hydrogen 4wt rods and Battenkill IV clicker reels with mono running line, skagit head, tips, leader and fly. At the end of class we where offered the complete outfit plus some extra tips below dealer cost. After spending a few days with the Hydrogen rod I jumped on the deal because I really liked the rod and it was a great deal. I have added a few more rods to my quiver since then and all are upper end rods. They all have their own personality's some more forgiving than others. When I get all messed up trying to cast because I've not done it for a while I get the Hydrogen out to get back in the grove because it's very forgiving and gives great feed back to what I'm doing wrong. The only complaint I have with it is the cheap cork used in the build but understand that's what you get at this price range. After repairing, filling and sealing it's fine now.