[UPDATE] Have a look at www.xero.com
In short: Quickbooks is better. It has more features and is easier to use.
Hopefully I can save you some time evaluating accounting systems. We’ve run both packages in our business and even had a consultant (who’s an expert in both) come and see us.
At some point someone (typically someone smart, with an accounting background) will tell you to use Pastel. For some reason it’s popular with accountants.
Have you ever heard about how, in software, when you have a bug you simply re-write the manual and call it a feature? Well, that’s what Pastel did.
So whenever someone comes out in favour of Pastel, they’ll cite the old marketing spiel about how you can’t go back and change transactions (a bug) as if that’s a good thing. They’ll say that Quickbooks makes it easier for someone to commit fraud. This is not true: Quickbooks has a full audit trail, so even if someone did go back 6 months to “cook the books”, they’ll leave tracks.