There are the bugs I can remember.
1. Every time, you update your QB, the program will automatically recalculate all the old paycheques based on new tax table. For example, you issue a paycheque on December 31, 2004,for $2000.00 (net amount). If you upgrade the quickbooks to 2005, it will recalcualte that paycheque based on 2005 tax table. Net amount will change to $2100. As result of that, all your last year's bank reconciliation will be wrong.
2. Don't ever use these integrate feature like forecaste, budget or customer client manager. None of works. They will damage your data file.
If you issue your cheque manually, you won't have any problem. (Like create a regular cheque and manually post to different liability and expense accounts)
In this case, you don't have to pay for the payroll service..
There are tons of other bugs that will give you nightmare, like data verification doesn't detect all the problems in the data file. User has to manually check the data damaged based on several reports. You have to do this on regular basis to avoid future problem.
Yes MYOB can do payroll. I recommand you wait until November of this year, because MYOB will release a new version at that time.
I have never used PEACHTREE, so I can't comment on it.
I just remember there is a bug in online credit card payment in QB 2004, and 2005. I am sure not whether QB fix that or not.
So based on my personal experiences, QB sucks