I was looking at the released code for a VPN 3005 to accomodate the new DST change and see there are 2 releases - 4.1.7.Q and 4.7.2.K - what (if any) are the differences and when would I choose one over the other?
Both are different releases. I am forwarding you the release notes for the 4.1.7 F and 4.7.2
4.1.7 F :
You should be able to find the primary differences. E.g. SSL VPN client and Secure Desktop is only supported in 4.7.x code series.
Please rate if it helps,