After some fiddeling, I am now more or less installed at Logica CMG. Some systems still need configuring and I still have to place a few calls to India (where our support is situated) to get it all up and running.
At Convergence, I had the opportunity to browse around and talk to some of the ISV (Independent Software Vendors) that supply 3:rd party addons for Microsoft CRM. One of the companies I found was CWR Mobility that have developed a very competent mobile client for Microsoft CRM 3 (and soon 4). It is a much more mature product (from what I could judge) than the normal Mobile Client, and it supports sometimes-connected scenarios and offline sync, as well as an offline SDK. So, if you are facing a customer with mobility demands, be sure to check out their products.