I am consider a Dahon Presto Lite along with Dahon's Speed D7/P8 and Vitesse D5. I really like that the Presto Lite weights just 18 lbs while the other bikes weight between 25 and 27 lbs. Is there really that much difference with the reduced weight to make up for the higher price? Is it much easier for carrying and transport purposes?

There is a great three page thread in the general cycling part of Bike Forums (I started it) about the
physics of bike weight vs. rider weight. Of course folders have a different factor tossed in and that
is the fact that many buy them to carry around. I have a heavier folder (28#) and I would value
a lighter one. Five pounds riding is not as big a deal as five pounds carrying up stairs or handing
or lifting from your row boat over your head onto your boat deck (my sitch).

For me, and I think for most people, there is a huge difference between carrying 18 pounds and 27 pounds for any length of time; or as hbob says, lifting in an awkward position. If you intend to carry the bike a lot, definitely consider weight. For riding, it's not as big a consideration.

The question is, do you want a 16" folder? You should try one first before you even consider those bikes in the same weight category. To make it fair, you might be considering the weight difference of a Helios--there it's $600 MSRP for a savings of 2 pounds over the Speed P8 ($500).

In my experience, 20" is as small as I'm willing to go for regular city riding.

The Heilos P8 is the lightest folder at a resonable price last time I looked. Its 10.5 kg with no options but since all Dahons come with racks/guards and associated gubbins this is around 1.5 kg (2kg for the cheaper Dahons with steel racks) lighter than what you buy in the shop. Can you get the Vitesse D7 over there? Very light and excellent value (about €350 here).

A 2 kg saving makes the bike significantly easier to carry around, for me anyway. To affirm what other guys say the extra weight makes little difference in the way the bike rides, as they always repeat in the road bike forum - 1kg off you == 1kg off the bike.

Problem is though, if you get the Presto Lite your muscles wont be as big and unfortunatly your going to need them for punching people who laugh at you for riding what looks like a silly kids bike.

I like the Presto lite myself but it's really overpriced. If you are not intending to board the bus every day, then get a Dahon with 20' inch wheels. The Presto like the Brompton is all about compromise and the small 16' inch wheels will give a rough and twichy ride. As someone said, the 20' inch wheel is the best way to go unless you are using the bike for multimode transport involving the bus twice a day.

I had the Piccolo and needed to purchase a suspension seat post adding more weight to the bicycle otherwise, it was unridable after 10 miles!

For the price of the Presto Lite, you could get a Speed Pro which is a much better bicycle overall. Eventually, you'll want to do some longer rides and the 3 speed hub of the Presto will not be adequate.