Jeff,
Actually the IPSWITCH new product is the Collaboration Suite, in which you are correct. However the product I am referring to is their old version of the mail server, which was just their mail product and not the full suite.
Although the the IPSwitch product worked well, they wanted too much money to maintain the product annually as well as they wanted the company to upgrade to the new suite so they could support it. Their has been a MASS exidous from IPSWITCH in the past year because of thise and most of the customers who did not like their new model went to other Windows solutions, while a few went to Linux flavor's.
Don't get me wrong here, the Collaboration suite is a nice product, but in testing when we went to around 200 users it started to become a resource pig, and at 300 it was horrible. Sadly this was on a DUAL XEON machine with 2Gb of memory, SCSI 320 drives, the works ! Sadly, it just killed the machine. We proceeded to load Fedora 3 on the box and had DA put their install on it, now we have 2800 + users, and of that around 5% use IMAP functions and our processor sits around 1 - 2%.
As far as the Nutsmail suite itself, it adds a lot of functions to Squirrelmail that are not in the standard build, but as we know we can add those ourself easily. The great thing about nutsmail ( so i think ) is that it is a great cosmetic solution, and had a much nicer feel then the out of the box squirrelmail, not to mention the user has the ability to set the interface to whatever style they wish ( around 50 styles in there ).
For a $49 usd pricetag for all 3 skins, plugins, and 4 months of upgrades I don't think that it is an unreasonable price to pay for a much more friendly cosmetic feel, and some nice functions (
http://nutsmail.com/features.htm ) ...
However that's just my opinion.
-rob