Okay here's my position...so far...
The 140/165 combo works really well if you are set on the mako feel, the mako performance and what a Mako has to offer. The king can be pushed and useable to the upper range of a kite you may be on. Hence easy to change to the 140 and continue.
I still maintian the 165 is the best wave rider as far as TT's go...it truly is a great board for carving as close as you can to a SB without being on one.
The 140 is a little ripper, can hold down big winds and yet carves enough for powered work in the surf.
But ....I know some mako riders mat not agree, but I have tried every possible fin size, position and footstrap setup...round edge are just not agreeable to true load and pop. Sure with technique you can dial into an acceptable degree in this area, but when you want to leave the water vertical and quickly ...round edges aren't superb. Also unless you have the mutant fins in, that back end squirrells out at high speeds with high load. Front foot pressure can minimise this, but you can still feel it and unless you get the technique right, it will do this. A side mutant fin reduces this quite a bit, but completely. (Also the King is too heavy for really pushing it, well for me anyhow I was pulling stomach muscels a lot). But in my opinion in mutant mode it really loses enough of its smooth carve feel, that made me come to the conclusion:
1. Keep a mako for carving in the waves, maybe some cruise sessions, that still allow some freeride boost, looping transitons etc etc...
2. Get a square tipped popping board for flat water or flattish ocean days.
That is use the mako for what it does best instead of trying to fit it around all aspects.
Get a Square tipped TT, for what it does best.
Get specific about your use and board choice.
Also I was riding my mates 150 a lot. It is the smoothest of all the sizes, the length, versus width, given the concave, just seems to provide the smoothest ride. Not as good as the King in the waves, but better than the 140. But not as easy to got nuts and throw around than the 140. Really sits in the middle, but from my experience the best 'mako' ride.
So haven't explained all the intracsies but you get the idea.
So far my decision has been spot on. The mako is a true carver as a TT, not a pretend one like most TT's try and mascarade as. But it is not easy to pop, load and throw around....
Instead of having an allround board, that doesn't do everything that well, get boards that do very well and what they are best at.