IceWarp vs Zentyal comparison

I've taken a look at a number of groupware servers including open exchange, Zimbra and Zarafa. I would have to say that Zarafa is the one that has come out on top in my experience so far. The main thing I was looking for was functionality like exchange so the service would appear the same to end users as the old exchange environment they worked in. They were Outlook users etc. Zarafa has its own version of Active Sync called Z-push which was an important feature for us. It has a very neat webapp which users like using and perfect integration with Outlook using native mapi. I've started using it for a number of customers as we are an IT company. The professional edition is EURO 28 per user per year, there's a small business version for EURO 16 per user per year and a community edition for free. I've also put customers on the cloud hosted version from The Email Laundry as it bundles in their email security and comes with a 25Gb mailbox. I'm afraid Ice Warp is one of the few messaging environments I haven't worked with. I was reasonably impressed with the OX app suite but the support was a big additional cost as far as I remember.