there are many views on task killers and many other aspects of android, and most if not all come down to your personal preference..
just like some things work on some phones and other don'ts, every phone along with its user are different.. [some phones can handle a 1.3 ghz kernal, others can only handle a 800 mhz kernal, there all different.]
this is my personal preference, i use a task killer..
here is what i have for everyone interested..
i wipe my phone, whenever flashing a ROM, or anything, and after each new release of SD, i do the same..
i use the following to backup settings and such on my phone
-SMS Backup & Restore from DEV Ritesh Sahu [its free, but its a great program and i personally have donated to the DEV, he made a great program, best ive found/used]
-Backup Bookmarks by DEV Kazuyuki Eguchi [not very aestically appealing, but works flawlessly]
-Advanced Task Killer from ReChild
when flashing, i backup any contacts onto my SD Card just to be safe
then i backup my bookmarks, and SMS messages [i use the bookmark program, cause when google restores your bookmarks, they dont restore all the cookies and everything, the app i use saves everything, cookies, cache, passwords, your browser will be exactly the same after you restore the bookmarks
then i would wipe data/cache and the cache partiion
flash the ROM
then for some odd reason i wipe data/cache and cache partition again.. idk y.. lol
reboot
after signing in and syncing with google **see following in
[*] i restore SMS, and bookmarks,
**[remember after you sign in let your phone sit until it restore all your apps]
**[some say this doesn't work, but it does for me everytime, free and paid apps, just sign in and put your phone down for 15-20 min.. then restore SMS and bookmarks
after this i reboot the phone, and after booting, and the phone finishes scanning my SDCard and after the 3G icon stops sending/recieving data, then i use a task killer..
i don't use a task killer again, unless my phone starts lagging, or an app is taking a long time to load..
i also reboot my phone daily, some leave it on for days, but i shut my DROID off and give it a rest every morning when i take my shower..
thats just what i do.. lol..
**also in advanced task killer i use the ignor list, and exclude, email, gmail, Messaging, and facebook.. so use the ignor list put the apps that you want to keep running/updating on it..
ex. if you want email to update as it should then you can't kill it; same with facebook; and any other app that needs to update..