I have G1 over a month now. Here are my observations:
I took it with me on the around the world tour and it holds up very well. It is very lightweight with the standard battery ( only last about 5.5 hours in real life, advertised 12 hours). I used it mainly for minor photo editing, watching recorded videos on the plane. Usually flight time on the plane range from 3.5 hours to 7 hours each segment. If I have to burn dvds, it will last less than 4-4.5 hours based on my estimate (burned 3 dvds on board one of flights). G1 screen is only a bit better than Panasonic laptop (compare with my Panasonic W2, T4), it is definitely less bright than my Sony TX (TX651).
I have many laptops and I find 12 inches screen gives me the best usage traveling aboard. I can watch dvd, photo editing, writing emails on 12 inches, anything less than that, it hurts my eyes after a few hours. That is the reason I carry G1 instead of TX651 for this trip.
G1 is definitely not a fast machine. It is comparable to any laptop currently using Core Solo cpu. If performace is what you must have, SZ model is your best bet.
Again, I have to point out G1 is very very lightweight. With battery, you can still hold it with your two fingers. I carry it on my backpack even during the tour.
If you need your computer more than 5 hours on battery, you can either invest another battery (not heavy or big like TX's extended battery) or get Panasonic laptops. You sacrfice screen for longer battery life. Panasonic screen is not sharp,nor bright. That's the downside for superlong battery.
G1 ac charger is tiny as well. So is Panasonic. G1 is also well build, I dropped my G1 inside my soft case flat on the ground from table, no scratch or any dent. Maybe a few scratches on the surface after this trip, but it did survive Cuzco and Tibet (high altitude) without any problem.
Oh, both W5 and G1 use slow hard drive I think. So both are definitly not peformance machine.
Thanks for Mr.Lin's information! That's really helpful! I'll take a look and try it someday in the Sony showroom then make a decision as well! Anyway, thank you very much again!