I'm 6'3" (barefoot) - used to be 6'4" when I was younger - just the way it goes at 65. I weigh about 205 dressed and have a 6'6" arm span.

I have both a Dahon S1 and a Bike Friday NWT. Until I got the NWT a few months ago, I also had a Dahon Boardwalk D7.

I use(d) Thudbuster seat posts on all three bikes as they are more comfortable and also offer maybe a 1/2" more seat post extension on the Dahons. The 'Biologic' stem riser on the D7 gave adequate reach, but I have installed short bar ends on the S1 to make the position comfortable. The S1 is a 2005 model and has the vertically adjustable stem which greatly helps achieving that comfortable riding position. I have ridden 20-25 miles on the S1 several times.

My custom made Bike Friday, on the other hand, is an XXL sized frame (62cm effective top-tube length). The bar ends are just to give me a different hand position.

Have to add one other opinion: The NWT is far faster and easier to ride than either of the Dahons, period. The wife feels the same about her Pocket Crusoe vs. her old D7.

We are out here in an RV park in Cannon Beach, OR as I write this. Even though it's a bit cold and has rained on and off, we have managed to get in a couple of bike rides in the last five days. It's also nice to have the bikes stored in our 4Runner, both safe and out of the weather.