I have very little lag. It's there - the phone's not as fast as it is on stock - but it's not a deal breaker for me. Theming and video recording, the reasons for which I jailbreak, easily make up for the lag.
The lag (if any real noticeable amount) is dependant upon the number of add-ons. Theming, background task capabilities, call/sms/im reminders, etc all take horsepower, but only when used. Personally, I've added about 80 AppStore apps and it appears to slow down a bit with each additional app loaded --- doesn't matter much whether it's from AppStore or Cydia (jb'k app installer). A fresh/clean/virgin phone will always run faster.
There is no more lag then there would be with a stock phone that has a few apps from Apples store. I have mine JB again, with some really cool stuff and barely have/notice any lag. Only lag i get is when installing cracked appstore apps.
I don't think it's quite that bad, but jailbreaking certainly does let you have those apps that are missing from the stock iPhone, i.e. copy & paste and video recording. MxTube and dTunes are also musts for me.
I read stories of people saying it takes up to 6-8 seconds for camera and sms and other things to open after JB'ing
Also they need to reboot all the time to speed things up and they get a lot of crashes.
Is the flakiness inherent to JB'ing?
If I do JB and don't like it and revert. Will I lose my usage totals and contacts and sms etc etc? (this is a biggie for me)
Back up before you jailbreak, then you can restore from that back up when you/if you go back to stock, you will lose anything done between. Purchased apps will resync but sms you receive while jailbroken will be lost if you go back, you will almsot certainly lose your usage data, but you will lose your lifetime totals from the upgrade in firmare anyway.
FWIW I haven't restarted in several hours (reset to get my signal back after the outage) or resprung and the camera takes approximately 2-2.5 seconds from tap to the "aperture" open, sms takes about the same (in fairness though I only have the sms I've received/sent since I upgraded to 2.2.1 and re-jailbroke), photos opens up to album view in 2 seconds. Mail's always running in the background so it opens immediately.
Well, you're getting lots of opinions here. Suffice to say that the lag is not universal, but varies from unit to unit, for some unknown reason. I don't think anyone here can make a blanket statement about jailbreaking and lag unless they've done it for a LOT of phones. But there is definitely the risk that you will experience unacceptable lag. This will also vary person to person, so it's really impossible to say if it's worth it to you.
>>>> Suffice to say that the lag is not universal, but varies from unit to unit, for some unknown reason.<<<
Thats what I'm saying.. I think some phones work better than others before anything.
Also when you consider the 'lag' or delay are you trying to close something out and it has not finished doing its thing? is it checking for mail in the background? I think all thing can effect it. I think... but I don't know sh!t