Hi Daniel,
Apologies for the slow response. Have been busy moving house.
Originally 6 or so years ago I had the same intention - to kayak in creek boats from Harnett Falls down to the lake although I intended to come in from Narcissus via the OT. This idea then changed to heavy inflatables and finally to lightweight packrafts. It was only in the final stage of preparation for this trip that I discovered that two others had already kayaked it. Not that this changed things other than discovering that it could be done. Having now walked/dragged/carried/paddled packrafts down there I would no longer contemplate taking kayaks above Lees Paddocks given the limited opportunities for them to perform to their potential. I feel as though there are other rivers out there that have only had a single descent (or packraft only descent) that would be a lot more deserving of a full-on walk in kayak trip.
That said I never wish to discourage others from having crazy adventures! Certainly carrying a creek boat in to the bottom end of Lees Paddocks is likely to be worth it given the relatively minor effort required (comparably). This section of the river is very diiferent in character to much of the upper sections. At the right level (high) Lees Paddocks down would be fantastic in a kayak.
The section from perhaps about 1km upstream to junction of Kiaora Creek would certainly have a SHORT section of good kayaking in it but its a much bigger task to get into there and from the junction to the bottom of Lees is essentially tree-chocked.
Yes paddling a creek boat gives me great (relative) control but the biggest surprise for me with packrafting has been how much fun I am having in them - I have to admit I rarely feel the urge to pull out the creek boat these days - but perhaps I am just getting old. I always thought packrafts would simply be a practical craft but never realised just how much fun they would be even for a (previously) very keen WW kayaker.
I spoke with one of the guys who kayaked the same trip as us just before we left and he was pretty negative about the river and I think rightly so as for a kayaker, even discounting the walk in, it is generally too easy or there are too many trees… To them the main waterfalls were also obstacles to walk around whereas for us they were great fun as we got to combine packrafts and ropes. I think they thought we were crazy to bother taking ropes when you can get around each of the waterfalls with no more than a throwrope if you wish. Even if I could heli in I still probably wouldn’t bother kayaking it.
That said if you are anything like me having someone tell you it’s not worthwhile will probably only make you keener and more determined to do it. 
PM me if you want to contact the guys who kayaked it directly.
Good luck with it and let us know if you do it.
Cheers Mark