All of these comments are valid.
If you only intend to ride in TT mode I would go with the 140 or even possibly our new 135 size, the Makos have a ton of get up and go so no worries on the size (I am 180lbs and ride the 130cm Mako Mini with a 8 or 10m kite almost exclusively).
If you want to explore the mutant options but don’t want to go up to the King the 150 is a great compromise. It handles well in TT mode and is a lot of fun in mutant. The only real draw back to the 150 is that it has so much surface area it can suck down to the water surface and need to be released off it’s edge (not flat) when trying to pop to toe side or chop hop…
John Z - OR