I'm using 4s on 6.1.1 for about a week now..my combo of tweaks are;

a)sbsettings
b)auxo
c)winterboard
d)activator
e)bytafont
f)mytube

that's it..so far,ididnt encounter any unstable tweaks..but i believe its the tweak u choose to compliment each other, n also how u configure them so that it doesn't have a redundant functions..for example,auxo n sbsettings have almost identical functions..what i do is i hide any toggles that i didn't want in SBSettings but enable it in auxo and vice versa..especially the brightness toggle where both of them have.

Also,i didn't use any heavy or HD stuff in winterboard,i just use the simple 'IOS5 NewEra' theme which doesn't consume too much memory,yet its looks 'different' than the stock icons..same goes to themes for sbsettings n auxo.

But i do encounter some low memory situations but mostly when i'm opening too many apps,especially HD games..but that's not a big deal for me..i either free the memory or respring and i'm good to go

This post has been edited by maderfader: Feb 18 2013, 04:50 PM

My 4s ios 6.1 jailbroken has drain the battery alot..but after upgrade to 6.1.1 jailbroken,it has improves..but not excellent..based on battery performance in standby mode on jailbroken iphones histrorically, i can simply put 4.1(ip4) > 4.3.3 (ip4) > 5.1.1(ip 4 & 4s) > 6.1.1(4s) > 6.1(4s) ..as i said before i used light tweaks only,i'm not a heavy tweaker.. almost all of them used the same tweaks apart from auxo which available on 5.1.1, 6.1 and 6.1.1

This post has been edited by maderfader: Feb 19 2013, 12:51 PM

Actually i have no problem on FB and whatsapp apps,i know this coz i use these apps very frequently..as for the 3G,i'm using maxis..i don't know if the problem is related to service providers,but i don't encounter any problems so far,exactly the same as before..what i do know that my 3G is alot faster since about a month now..but thats definitely not because of ios, its because maxis itself upgrading its network performance..if u play 'Rage of Bahamut',u'll know what i'm talking about

Could be,coz i never installed the tweaks u mentioned at all