I think the double vibrate for texts is cool but I dont know if that's enough to make me upgrade. I have a replacement i4 that came with 4.2.1 a few weeks ago and used greenpois0n. Now dev team has an untethered jailbreak for 4.3.1 (used redsn0w last night on my iPad first gen 32gig I picked up from Verizon over the weekend which came with 3.2.2 stock and was REALLY outdated so I updated to 4.3.1 on it -- and LOVE this iPad, especially since it was on clearance). But now that it's a jailbreak option (4.3.1 that is), what do you like about 4.3.1 over 4.2.1? I know "if it's not broke, don't fix it" and I generally prescribe to that philosophy, as I was using 4.0.1 on my original launch day i4 until 4.1 got jailbroken by geohot a la limera1n and then 4.2.1 (and replacement swap) when greenpois0n came out... but I'm just curious!