I got to try out quite a few twin fin boards this year plus some other multi finned boards and my favourite was the RRD 82 twin!
I tried it out in cross onshore conditions at Scarborough with a 5.3m and my new 77kg
I'll keep it brief.
It planed fairly early, had reasonable top end speed and in a straight line it felt "lively" one other board felt more lively, but the rrd had a nice responsive feel. It didn't spin out or let go once. If your used to single fins, then in a straight line you probably wouldn't know it was a twin fin.
On the wave it could do tight little turns and big drawn out ones unlike some of the others that I tried that had a very locked in radius, this board felt very intuitive just point(where I wanted to be) and shoot! What I liked most was that at the half way point in the turn where the other boards started to bog and slow down, the rrd didnt it kept it's forward momentum for some very nice powered up top turns, one other board I tried also had this "drive" but the radius of the turn could not be made tighter due to the flatter rocker.
Two other boards of another brand had a more grippy feel when the rail engaged, but for me in cross onshore conditions the extra drive that the rrd gave back up the face out weighed this.
Also why I really, really liked it was because it felt very similar to my own custom board.

I highly recommend getting hold of one of these RRD's to try out. I dont think they changed the shape this year and I can see why.