Both settings are doing reaaally a little to nothing. I believe athat all HDTVs after mid-2009 have really better scaller than the one found on PS3 so I always turn it off, believe it or not the results are better. The smoother tends to make text unreadable on PSOne games since they are all running at 320x240i@60Hz and it gives a weird blooming effect on games with white and black objects (I'm sure it's not my TV's fault, I can see that on 5 different TVs).
I can make a visual example how those effects/settings look in practice if you want...
...and the worlds shall reconnect