Yes, using Google Apps (even the free version) for email results in very few of your outgoing mails being marked as spam.
Note two downsides that I've come across (these are present in all paid editions too):
1) If you don't have access to the server's DNS zones (as is often the case on a shared server), you wont be able to add an SPF record for your server's IP, which will increase the amount of your emails being marked as spam.
2) Google Apps deals with multiple domains quite badly, in my opinion. If you have domainA.com as your main Google Apps accounts, with domainB.com as an additional domain, then if you send mail from person@domainB.com, the headers will show From:person@domainB.com
but Return-Path:person@domainA.com
. In some clients, such as Outlook, this shows as From person@domainB.com on behalf of person@domainA.com
and a large proportion of mail servers will mark it as spam.