I've been enjoying 5.1.1 Untethered for a while (Old bootrom 3GS of course), and I've got to say that it's worth the jailbreak.
Here are some other tweaks to keep in mind:
5 Icon Dock
-Pretty much what it says.
-With 'Scrollingboard' you can get a custom number of icons in the dock, but you get the music controls found in the multitasking menu if you turn the page left, multiple other plugins, and if you turn the page right, you get pages for your dock.
-Scrollingboard costs money though, 5 Icon Dock is free.
Barrel
-Different icon animations for scrolling through pages on your springboard. If you used it before, it has a handful of new icon animations. I'm sticking to Cube (Outside) though.
-Also costs money.
WeeRoll
-A lot like Barrel, but it gives an animation for your main screen when pulling down the notification center. I have no idea how it would work on the iPad, if at all.
-I'm pretty sure this cost money also... I don't remember.
WeatherIcon
-Just nice if you actually look at your icons. I get annoyed by the weather app icon always suggesting it's sunny and 73. Also, there was an tweak called LiveClock, which offered a similar thing to the clock app. I don't think it's been updated though. It's not always 10:15 damnit...
-Both are free, but I do believe that LiveClock hasn't been updated.
SBSettings
-Quick toggles from anywhere that has a status bar, and some other system info that can be quite useful. It also has a fake carrier option, along with the ability to put the date along side the time in the status bar. And you can also get the free system memory, which is quite useful when you're multitasking a ton of apps.
-I haven't installed it since updating to 5.1.1, and I have recently realized that it is quite the resource hog. Still really useful, but with a 3GS you might want to reconsider. If you're running a 4 or 4S or any model iPad, it should work well enough.
-This one is also free.
Pinned Nyan
-Animated Nyan Cat in your notification center pull down page. If you tap it it plays the song. Not really that useful other than annoying coworkers, classmates, teachers, etc.
-It is in another repository, so you'd have to google it.
-It is free.
I can't think of any more at the moment, but I hoped this little list helped.