mostro,
Personally, I find the 13" to be the best overall size for travel & work. I've owned 8.9", 10", & 11.6" netbooks. I've owned 13", 15", & 17" PC laptops and 13" white Macbook and my 13" unibody MBP.
The netbooks were fantastic for travel. I threw them in whatever I was carrying (including zip-up planners) and went on my way. The problem came from actually USING them. The very large majority of them have only 572 or 600 vertical resolution and you end up cutting off the bottom of dialog boxes and windows and end up having an overabundance of scrolling for pretty much everything. The larger netbooks do have a more useable 768 vertical resolution but they still suffer from the other netbook deficiency of a lack of processing power. The 1.6 Atom processor is great for web surfing, email, & light word processing but is completely overwhelmed if you need to run multiple programs at once or do any kind of more intensive work. It was enough for me to get rid of them and go to a 13" Macbook which was a massive improvement in functionality while only slightly less portable than most 10" & larger netbooks. I liked it so much that I sold it (I bought it off a friend that upgraded) and bought a 13" unibody MBP. Oddly, the small differences in size & weight are noticeable for traveling. The only negative is that the aluminum surface is a bit slicker than I prefer.
As for home use, I think that really depends on the person. I have relegated all my other laptops to other uses now. My 17" is sitting in my office where I haven't turned it on in a few weeks. I loaned my 15" to my parents so that they'd both have a laptop that they can use without the other one closing their documents or otherwise screwing them up. I use the 13" MBP as my every day computer now and haven't really had too many regrets other than the occasional wish for a larger screen while watching a movie or something.
Thanks much for this very informative post. Great to get a perspective from someone who has owned every size laptop under the sun ;D
I actually have a Mini 9, which only really gets used in the kitchen for looking at recipes while cooking, and if I travel somewhere. I think I might replace that with a Mini 10V anyway since the keyboard on the 9 is so cramped.
At any rate, its interesting to hear that the new 13" MBP is noticeably more portable than the older polycarbonate models. Its funny how much difference a really little bit can make.
Also, something jukeboxfun mentioned that I hadn't thought about is the newer trackpad supporting pinch zoom in the web browser. I often use ctrl+scroll, but pinch zoom is easier.
Too bad I don't have the budget to just own every size laptop at once and use the one that's right for the day, LOL.
Funny, i'm actually typing this right now on my work-provided Dell which is a 14" screen at 1440x900 (same as the 15" MBP), which confirms my earlier belief. This resolution is perfect for 14" and not too cramped, versus the 13" 1280x800 which I feel to be cramped. But for the 15" they should have gone to 1680x1050! (Apple, are you listening! We all know new Core i7 MBP's are coming soon, bump that resolution when they come out!)