Personal preference shirley, if you have small dainty hands you will probably prefer a smaller handset. Depends how you use your phone as well, if you just want a phone to make calls and send texts then a smaller handset does the job perfectly. If you want to view web pages, play games or watch movies for example then a bigger screen has got to be an advantage.
My current Nokia 5310 is very small by todays standards but as it has proper numeric keys I find texting to be failry easy even with my erm man sized hands. The current generation of phones with a touchscreen at the same size are a complete nightmare in comparison.
I was tempted to upgrade to the HTC OneX but was holding off for the S3 to be released. The fact the S3 has a removable battery (without stripping the phone to bits),a SD reader and a higher capacity battery has swayed my decision. Size wise there is not much in it going off the tech specs of simillar phones, S2/S3, OneX etc. Also the S3 looks to be failry light as well so even though its a big phone I doubt you will notice it much when its in your pocket.
A big phone is handy if your a buisness type as well, the current generation can pretty much replace a laptop as well as making calls. It is amazing how much a smart phone can do these days compared with one from say two or three years ago.
EDIT: Should really read the whole thread before replying, +1 for Sliced Bread...