For me, most commercial VPN services have worked fine. PPTP VPNs are blocked/flaky on mobile data plan connections (maybe by the phone company), but no real is

For me, most commercial VPN services have worked fine. PPTP VPNs are blocked/flaky on mobile data plan connections (maybe by the phone company), but no real issues on wifi. On 3/4G, Shadowsocks works perfectly and corporate VPN (Cisco/IPSec) have no issues.