I have my own Crossbow 16, but I heard that Swtichblade is more powerful for low end wind condition.. True ? I am not sure about SB turning slowly.. hard to get high jump..and heavy bar pressure like Crossbow.. I am thinking of getting Glide for light wind condtion.. ( 9- 14 knots ) Is it true that it is easy to ride Glide in choppy water ?? Which board is more popular to ride in the light wind condition.. My weight is 200 lbs

If you have the CB 16m already, the Switchblade 16m isn't going to be much more(if any) of a difference in terms of low end. The CB 16m is plenty kite for 9-14 knots with the right board. With the Glide, you can easily be powered up and having a blast in those winds. The Glide does okay in chop, but it is practically flat with no rocker. So, if it is super choppy or you are trying to ride waves with it, it isn't the board. But usually at the winds that you would need the Glide(9-14), there isn't that much chop or big waves. At least not in Florida.

So, for super light winds: get the Glide, a surf board, or a big skimboard. Any will work.

Really... A friend of mine wanna buy my CB 16 so badly this month , so which big kite do you sugggest me to buy for light wind condition? SB or CB again? or another brand like Sonic or Ocean Rodeo One ? Thx

The 16 CB would be fine for you, unless you really want to sell it to your friend. If so, then you could do just as well with a 16m SB or even a 14m GK Sonic. I talked to several guys that rode the 14m Sonic and did just as well or better than other guys that were on 18-20m C shape kites.
If you want an awesome light wind C shape kite, then the 20m RRD Type HIR or 21m RRD Type 7 can't be beat. They turn as fast as most 14m kites, but have the power of 20's....