Google Apps vs Exchange 2007 (hosted) for non-profit of size 60

We are an engineering-oriented non-profit with a significant number of Linux and Mac OS desktop users. We are looking to move our email / calendaring solution to an hosting provider.  The question is, which solution is best?  Here are leading considerations:

• Exchange 2007 / Microsoft Business suite:  Good for Windows and IE users; hard for others. Expensive. Does not come fully loaded with document management, etc. Extras cost more. Has enormous market share.
• Google Apps: Affordable. Not biased towards any specific operating system. For Windows / IE users, it could take away features they like (i.e., provided by Exchange).  Not proven in the marketplace.
• Zimbra, Zoho and other similar solutions: Very much like Google Apps.  Is there something about these that makes them better than Google Apps?  Zimbra is owned by Yahoo and that makes me nervous.

Does anyone work for or know of a company like us?  Have you seen Linux users that use Microsoft Exchange and really like it?  Have you seen Windows / IE users that use Google Apps (or similar) for work and love it?

Let me start out by saying I do not totally agree with your assessment so am not sure if the following helps or not.

Here is my two cents:

Zimbra hosted or on your own is one of the best products. It  provides much of the functions of both Exchange and Google Apps. I use Zimbra for a home/family on an old dell server.  Yahoo, the company, is making yearly profits, its investors are taking a bath http://yhoo.client.shareholder.com/sec.cfm?DocType=Proxy.

I use  Exchange at work and have not used anything else since 2000.   I am not sure about what you mean "hard for others"  using imap or pop any  good mail program can hook up with exchange. I have used OWA with Opera and Chrome without ant issue and Firefox (which provides a different look and feel). Exchange has so many third party apps that you can make it do just about anything including  project management, NPO get a great deal on Exchange here at Techsoup. If you are in a Linux environment use http://www.bynari.net/ with or without exchange. If you use SBS then you will get lots of extra functions. The intergretion with Office Live reduces the document management issue.

Google apps is well tested. Many colleges and some businesses use the education edition, without many issues. http://www.google.com/a/help/intl/en/edu/index.html

Hosted Exchange  for 60  people is fairly expensive ($600 per month) so if I was looking for hosted use Zimbra  ( at $250 per month for a whole server) or google apps education edition (free).

For pure functions Exchange  gives you the most number, deepest, and most mature. It also does sharing information the best.

Zimbra  Server is the great, cheap, and allows a Exchange like experience.

Google Apps allow the person to take it with them if they were to leave the organization (good and bad here),  the apps are good but they do  not connect as seamlessly as with Exchange or Zimbra, IMO.

We are a non-profit of about 110 exchange users.  We are running 03 exchange and will have to upgrade within the next year.  I have been contiplating the move to a hosted environment.  We also have Cisco call manager/unity for our IP phones and use the unified messaging through outlook.  I have seen that there is the ability to retain unified messaging w/ cisco using the unity connection which would allow the messaging to be used in a hosted environment.  I am in need of cost comparision for these situations and also a hosted group that would give us similar functionality.  So I am interested in hearing if anyone is useing the hosted environment with unified connection. 

Thanks.