We have just completed a successful deployment of our site from our dev environment to our test environment using Courier 2.7.0.29 (using a few workarounds for some issues we'd discovered).  I see there has been another 3 or 4 builds since & this may mean some of these workaounds aren't needed - when we have time, I'll try the newer builds.

One issue that we did have with this deployment was, after our initial courier deployment which appeared to complete successfully, we had some masterpages that didn't have the correct content.  Files that should have been around 50 lines long just had the following (as an example):

<%@ Master Language="C#" MasterPageFile="~/umbraco/masterpages/default.master" AutoEventWireup="true" %>

<asp:Content ContentPlaceHolderID="ContentPlaceHolderDefault" runat="server">
</asp:Content>

We managed to track this down to being caused by certain files in our filesystem being read-only (probably marked as read only by Team Foundation Server).  Making sure that there were no read-only files before the extraction worked fine.

Not a huge issue, but I'm sure other people will probably come across this at some stage - maybe it would be nice either to remove the read-only flag or have an error displayed to the user to say what has happened and why rather than saying that the extraction completed?  (Incidentally, on running the same package a second time, we do get an exception saying can't get access to a read only file).

I must say, the latest versions of Courier are looking very good though - and the speed of packaging and extracting is very impressive for a large site such as ours!!