It's been a few years since I paddled the 10'10 .i thought it was pretty good ,nice and stable and holds a nice straight line with the channels .
been wide it felt big.I did have a 11' glide which felt similar .
but I prefer the narrower 11'4 ,the wider boards are more stable but do feel a little draggy .
have you thought of getting a flat water board .eg .glide or javelin.
when I flat water paddle now I use a 14' javelin .
you could even get a 12.6.or 11,6 touring glide .
but it sound like you are gunning for a small board .
you say you have a 10.6 Nalu .its similar feel to the 11'and 11'4 ,
my daughter who is 13 ,fly's on the 11'4 .its the Gt so she can carry it ,at 11.4 kgs .
i struggle to catch her on my 11' .basically because the 11' has heaps of rocker for surfing .and Im heavier.
the mana s are wave boards ,but do flat water paddle quite good ,as they do have quite a flat rocker .if your not in a hurry ,and want the luxury of a small board they are good

.some times I can't be bothered throwing the big board on ,I'll throw the 9.5 mana on and just paddle around in still water .
looking at the reef and just floating .If I need to do some distances .the Nalu or Javelin.
Im 94 kgs.so the 9.5 is still in my range .
hope this helped.I still think the 11.4 it's got good speed and its light .surf too ,you might go on a trip somewhere ,your covered.