Honestly it depends on what your goals are.

The crazy 88 has less volume in the bow area which makes bow initiations a bit easier on flat water. However it is a bit more of an edgy boat, which makes river running a little more technical and bigger water too.

The Kingpin is a great all around boat, it has a bit more volume up front, and in my opinon it is a little harder to learn flat water moves with it. However for river running it is a faster and more forgiving vessel.

Now for a slice of my personal philosophy. I have paddled both the kingpin and crazy 88. I personally prefer the kingpin. Although the crazy 88 is better on flatwater, once you have those moves down, the kingpin is perfectly capable too. So if I was choosing a boat, knowing that I can do everthing in a kingpin that I can do in a crazy 88, I would go for the kingpin, just because it has better river running features. I dig the super hardcore playboats, but we do more river running around here then straight big wave surfing like the skook. For that reason I would go with the Kingpin.

Now to cook your bacon.
I recomend against buying a playboat for the savings. A lot of people I know have done just that, and found that they are unable to progress with the boat they have. Some people just don't fit into a boat the same way as others, so although a we might be the same height and weight other things can factor into, don't just go out and buy a boat cause a buddy has one and he can throw down in it. Some people I know had to try 4-5 boats before they found that perfect fit.

Like Dave bouncing from King Pin's and ZG's to the final choice a Necky Chronic. Dave paid full price for his chronic because although he could get steals on other boats he only could throw down that chronic with super style. Someday dave might switch up after he learns the moves and can take them to other boats, but until then he only likes the Chronic.

So ask yourself are you ok with saving $400-$500 and being stuck in a boat that you might never be able to throw down? Or would you prefer to spend the extra money to learn the moves faster? Its a question that only you can answer. And many peoples answers are different. And most of all many peoples answers to that question change after they are stuck in that first boat!!!

My final long winded advice. Go to the lake with some boaters and try before you buy!

 I bought a crazy 88 6.3 this winter, I'm 6' 185lbs, I really like it.  I paddle the wenatchee and the lower tumwater.  It was a big improvement over my foreplay, I'm trying to learn flatwater tricks, I think it will all come with hours in the boat.

Tom, I think it is great that your skills and confidence have increasee/improved and that you are looking for another ride other than the tank you have been paddling, although the GT is a great boat from everything I have heard and seen.  If you want to, you can add a couple of boats to your demo list (G-ride, Booster 55), as I am currently floating off the coast of an undisclosed country in an undisclosed part of the world, hunting down bad guys for the next 6 months, and my boats are very dry and sad.  If you want to use them, just let me know by posting here or email me at greenfieldja@verizon.net and I will let my wife know its cool.  See you in January.

-Jeff