Had a brief hands on with the LG Optimus S today at the local sprint store. they didn't have it on display but was nice enough to pull one out of the box for me to play with.
from previous reviews, i agreed it had nice heft for a little phone. for those that like a small form factor smartphone, this is a pretty good device. does not feel like a toy.
i also agreed that it was smooth switching home screens, starting and stopping apps. remember, it runs android 2.2. also remember, it's not an 800mhz or 1ghz phone so i think that's why the browser does not support flash. that means it might not, i don't think, be able to run heavy apps, like intensive gaming app. didn't have time to try something like that out.
everything seems to work as expected without hesitation. obviously, it can be bogged down with heavy background processes and running apps, but didn't really get a chance to stress test it.
i own the samsung epic and had an evo for a month. i wouldn't get this for myself, but for someone who doesn't need a powerhouse (or want to pay the cash up front and extra fee), it's almost worth getting. i think it's a bit steep at $50, so my guess the price on this thing will drop pretty soon come holiday shopping.
here's a quick snap with it next to the samsung intercept: