Can Web Based VPN Solutions Do It All?

Bingo Foo asks: "My company is in the process of reviewing replacements to our existing multi-platform VPN, which has now been discontinued. I was under the impression that every major vendor's OS ships with a VPN configuration solution. What gives? Are these not standard enough? Are they not secure enough? not flexible enough? Regardless, our IT department is leaning toward a clientless, web-based solution, which frankly sounds too good to be true. Can simply directing your browser at the portal allow X11, NFS, SMB, AFP, ssh, etc. transparently through the firewall? Anyone have experience with Neoteris and their VPN?"