Curious does the slim have the PS3 logo on the XMB screen when bootup. Or is that an addition to the new firmware? I ask because the PS3 fat didn't have it and I was wondering if they had the same updates installed.
I think that the speed gained by loading a game seems to be the fact that the ps3 slim doesn't show the playstation logo when starting up the game vs the old ps3. The old ps3 has about a 1.5 - 2 seconds time on the playstation logo and assuming that the old ps3 doesn't load the game when the logo is displayed, then the time gained would be null as the difference between both ps3's seems to be that exact 1.5 - 2 seconds.
I've watched 4 blu-ray movies since I got my slim, outside of the 'longer' loading times (its still faster than my old standalone player was). I haven't noticed any issues with blu-ray playback.
7 seconds is worth the reduced noise though, the slim is significantly quieter than the PS3 fat from my initial experience with it. When it comes to watching movies I'd say the decreased background noise of the player is a better trade of than initial load disc load times.
I (and I'm sure others) had an idea back in the 90's to have a N64 vs. PSX commercial where the kids with a nintendo put in a catridge, turn on the system, and start playing, while the kids with a PSX put in a disk, turned on the system, and waited the entire duration of the commercial on a loading screen.
Yes, loads times have reduced dramatically since then (and computer games loading off the HDD can be worse sometimes), but one or two seconds isn't going to change anything. Neither is 7 seconds for a movie to load (unless you put the wrong movie in, and are impatiently waiting for it to eject again).