I've been using OpenVPN for some time and it's in every way superior to the Cisco software and Juniper Network Connect software.
Cisco's client would drop the VPN connection when the laptop went into suspend mode. It also was configured to route all IP traffic over the VPN, so every network had added latency. It also had a serious bug where if it was terminated during establishing a connection, the connection settings would be erased.
Note that forcing all IP traffic over VPN meant that any existing downloads (podcasts or whatever) or connections to IM would be terminated. Then subsequently those connections would be terminated when the VPN was dropped.
Juniper Network's VPN client had similar network routing flaws, except did reestablish the connection after return from suspend, but it would "time out" (really it was forced termination) still after about 24 hours. But it also had a lengthy, annoying update and system verification process, meaning it could take 5-10 minutes just to reconnect.
The minus with OpenVPN is probably security. At Autodesk, I was using RSA's SecurID which is a safer than a private key stored locally on the laptop, although if I wanted to, my private key could be kept on a USB dongle, but still the RSA key can't be duplicated. Still either can be revoked in case of theft.