Two of the three new iSonic speed boards (the 52 and 40) arrived last week. Got to try the 52 the day I unpacked it (with the new Luderitz 5.7 sail - pictured) and managed a 41 knot 2-second.
This board is replacing the classic iSonic 55 (for me) and looks far more speed orientated than the slalom look/feel of the 55. The 40 has more volume (55L) than my old 44 (53L), so will be interesting to see how it goes being quite a bit narrower.
Got to try the 52 again yesterday with my 6.2 and it felt great. The board felt nice and locked-in and handled the bigger sail fine, and also the chop when bearing off (as the wind was very square to the run) - this should be my go to speed board when the wind is a bit flukey.
I've used the back strap positions (as I always do), but the mast track is further back than on my other boards and there's more front strap options, so will check the distance between the back and front straps and see whether I should be using one position forward of back for the front straps to have the same stance of my other boards.
Both boards have a great finish and look!
Video of setting the board up (not that interesting), together with the first run on it down the sand bar:
Boards look great Dave 
And I don't even think that video is sped up 
I was surprised how quick you were to be on the water after having to unbox them on the day! 
Makes sense now 
Love your 52 and that sail! Have huge luff section at the boom! Looks like it doesn't have a mast on it HAHAHA.
52 looks like my old school RRD 78 (278x53). It's a pleasure to ride with 6.2.
