After taking a look at the Hayden that would be my choice. The Walden is going to be very much like your new fun shape. Boards like the Hayden make riding a board the length of a performance shortboard feel like a fun shape. It is actually very similar to my new board I am picking up tomorrow
They generally have a lot of foam up front which makes getting into waves, and paddling in general, almost as easy as a board 1.5-2 ft longer. The reasonably flat nose and tail rocker makes it a great choice for those after work sessions where the wind has been on it too long and the shape is crap at best.
The concaves on mine are reversed from the Hayden though and I haven't ridden anything like that to give an experienced opinion on it. My new board is a Single/Double/Vee like my shortboards and my mini-long is just a Single/Double.
The first "short" board I rode after learning exclusively on a fun shape was a 6' 0" retro fish and I had a blast. A shorter board with that much foam is hard not to ride! You'll have fun and it will push you to grow and adapt.
I haven't ridden them yet but I'm going to try the PCs with the knub on the new board. I may pick up a set of Kellys later but I've been told I'll be very happy with these.